INTERNET-DRAFT
draft-ietf-ipp-model-v11-01.txt
                                                                R. deBry
                                                         IBM Corporation
                                                    T. Hastings (editor)
                                                       Xerox Corporation
                                                              R. Herriot
                                                       Xerox Corporation
                                                             S. Isaacson
                                                            Novell, Inc.
                                                               P. Powell
                                                     Astart Technologies
                                                       February 17, 1998

          Internet Printing Protocol/1.1: Model and Semantics

    Copyright (C) The Internet Society (1999). All Rights Reserved.

Status of this Memo

This document is an Internet-Draft and is in full conformance with all
provisions of Section 10 of [RFC2026].  Internet-Drafts are working
documents of the Internet Engineering Task Force (IETF), its areas, and
its working groups.  Note that other groups may also distribute working
documents as Internet-Drafts.

Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time.  It is inappropriate to use Internet-Drafts as reference material
or to cite them other than as "work in progress".

The list of current Internet-Drafts can be accessed at
http://www.ietf.org/ietf/1id-abstracts.txt

The list of Internet-Draft Shadow Directories can be accessed as
http://www.ietf.org/shadow.html.

Abstract

This document is one of a set of documents, which together describe all
aspects of a new Internet Printing Protocol (IPP).  IPP is an
application level protocol that can be used for distributed printing
using Internet tools and technologies.  This document describes a
simplified model consisting of abstract objects, their attributes, and
their operations that is independent of encoding and transport.  The
model consists of a Printer and a Job object.  A Job optionally supports
multiple documents.  IPP 1.1 semantics allow end-users and operators to
query printer capabilities, submit print jobs, inquire about the status
of print jobs and printers, cancel, hold, release, and restart print
jobs.  IPP 1.1 semantics allow operators to pause, resume, and purge
(jobs from) Printer objects.  This document also addresses security,
internationalization, and directory issues.

The full set of IPP documents includes:


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  Design Goals for an Internet Printing Protocol [IPP-REQ]
  Rationale for the Structure and Model and Protocol for the Internet
     Printing Protocol [IPP-RAT]
  Internet Printing Protocol/1.1: Model and Semantics (this document)
  Internet Printing Protocol/1.1: Encoding and Transport [IPP-PRO]
  Internet Printing Protocol/1.1: Implementer's Guide [IPP-IIG]
  Mapping between LPD and IPP Protocols [IPP LPD]


The "Design Goals for an Internet Printing Protocol" document takes a
broad look at distributed printing functionality, and it enumerates
real-life scenarios that help to clarify the features that need to be
included in a printing protocol for the Internet.  It identifies
requirements for three types of users: end users, operators, and
administrators.  It calls out a subset of end user requirements that are
satisfied in IPP/1.0.  Operator and administrator requirements are out
of scope for version 1.0.  A few OPTIONAL operator operations have been
added to IPP/1.1.

The "Rationale for the Structure and Model and Protocol for the Internet
Printing Protocol" document describes IPP from a high level view,
defines a roadmap for the various documents that form the suite of IPP
specifications, and gives background and rationale for the IETF working
group's major decisions.

The "Internet Printing Protocol/1.1: Encoding and Transport" document is
a formal mapping of the abstract operations and attributes defined in
the model document onto HTTP/1.1.  It defines the encoding rules for a
new Internet MIME media type called "application/ipp".  This document
also defines the rules for transporting over HTTP a message body whose
Content-Type is .application/ipp..  This document defines a new scheme
named .ipp. for identifying IPP printers and jobs.  Finally, this
document defines rules for supporting IPP/1.0 clients.

The "Internet Printing Protocol/1.1: Implementer's Guide" document gives
insight and advice to implementers of IPP clients and IPP objects.  It
is intended to help them understand IPP/1.1 and some of the
considerations that may assist them in the design of their client and/or
IPP object implementations.  For example, a typical order of processing
requests is given, including error checking.  Motivation for some of the
specification decisions is also included.

The "Mapping between LPD and IPP Protocols" document gives some advice
to implementers of gateways between IPP and LPD (Line Printer Daemon)
implementations.











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                           Table of Contents


1. Introduction.....................................................9
 1.1 Simplified Printing Model.....................................10

2. IPP Objects.....................................................12
 2.1 Printer Object................................................13
 2.2 Job Object....................................................14
 2.3 Object Relationships..........................................15
 2.4 Object Identity...............................................16

3. IPP Operations..................................................18
 3.1 Common Semantics..............................................19
  3.1.1 Required Parameters........................................19
  3.1.2 Operation IDs and Request IDs..............................20
  3.1.3 Attributes.................................................20
  3.1.4 Character Set and Natural Language Operation Attributes....22
   3.1.4.1  Request Operation Attributes..........................22
   3.1.4.2  Response Operation Attributes.........................26
  3.1.5 Operation Targets..........................................27
  3.1.6 Operation Status Codes and Messages........................28
  3.1.7 Versions...................................................29
  3.1.8 Job Creation Operations....................................30
 3.2 Printer Operations............................................32
  3.2.1 Print-Job Operation........................................32
   3.2.1.1  Print-Job Request.....................................32
   3.2.1.2  Print-Job Response....................................36
  3.2.2 Print-URI Operation........................................39
  3.2.3 Validate-Job Operation.....................................39
  3.2.4 Create-Job Operation.......................................39
  3.2.5 Get-Printer-Attributes Operation...........................40
   3.2.5.1  Get-Printer-Attributes Request........................40
   3.2.5.2  Get-Printer-Attributes Response.......................42
  3.2.6 Get-Jobs Operation.........................................43
   3.2.6.1  Get-Jobs Request......................................43
   3.2.6.2  Get-Jobs Response.....................................45
  3.2.7 Pause-Printer Operation....................................46
   3.2.7.1  Pause-Printer Request.................................47
   3.2.7.2  Pause-Printer Response................................48
  3.2.8 Resume-Printer Operation...................................48
  3.2.9 Purge-Jobs Operation.......................................49
 3.3 Job Operations................................................49
  3.3.1 Send-Document Operation....................................50
   3.3.1.1  Send-Document Request.................................51
   3.3.1.2  Send-Document Response................................52
  3.3.2 Send-URI Operation.........................................53
  3.3.3 Cancel-Job Operation.......................................53
   3.3.3.1  Cancel-Job Request....................................53
   3.3.3.2  Cancel-Job Response...................................54
  3.3.4 Get-Job-Attributes Operation...............................55
   3.3.4.1  Get-Job-Attributes Request............................55
   3.3.4.2  Get-Job-Attributes Response...........................56
  3.3.5 Hold-Job Operation.........................................57


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   3.3.5.1  Hold-Job Request......................................58
   3.3.5.2  Hold-Job Response.....................................59
  3.3.6 Release-Job Operation......................................59
  3.3.7 Restart-Job Operation......................................60
   3.3.7.1  Restart-Job Request...................................61
   3.3.7.2  Restart-Job Response..................................62

4. Object Attributes...............................................62
 4.1 Attribute Syntaxes............................................62
  4.1.1 'text'.....................................................63
   4.1.1.1  'textWithoutLanguage'.................................64
   4.1.1.2  'textWithLanguage'....................................64
  4.1.2 'name'.....................................................65
   4.1.2.1  'nameWithoutLanguage'.................................66
   4.1.2.2  'nameWithLanguage'....................................66
   4.1.2.3  Matching 'name' attribute values......................66
  4.1.3 'keyword'..................................................67
  4.1.4 'enum'.....................................................67
  4.1.5 'uri'......................................................68
  4.1.6 'uriScheme'................................................68
  4.1.7 'charset'..................................................69
  4.1.8 'naturalLanguage'..........................................69
  4.1.9 'mimeMediaType'............................................70
  4.1.10    'octetString'.........................................71
  4.1.11    'boolean'.............................................71
  4.1.12    'integer'.............................................71
  4.1.13    'rangeOfInteger'......................................71
  4.1.14    'dateTime'............................................72
  4.1.15    'resolution'..........................................72
  4.1.16    '1setOf  X'...........................................72
 4.2 Job Template Attributes.......................................72
  4.2.1 job-priority (integer(1:100))..............................76
  4.2.2 job-hold-until (type3 keyword | name (MAX))................77
  4.2.3 job-sheets (type3 keyword | name(MAX)).....................77
  4.2.4 multiple-document-handling (type2 keyword).................78
  4.2.5 copies (integer(1:MAX))....................................79
  4.2.6 finishings (1setOf type2 enum).............................79
  4.2.7 page-ranges (1setOf rangeOfInteger (1:MAX))................81
  4.2.8 sides (type2 keyword)......................................82
  4.2.9 number-up (integer(1:MAX)).................................83
  4.2.10    orientation-requested (type2 enum)....................83
  4.2.11    media (type3 keyword | name(MAX)).....................84
  4.2.12    printer-resolution (resolution).......................85
  4.2.13    print-quality (type2 enum)............................85
 4.3 Job Description Attributes....................................86
  4.3.1 job-uri (uri)..............................................88
  4.3.2 job-id (integer(1:MAX))....................................88
  4.3.3 job-printer-uri (uri)......................................88
  4.3.4 job-more-info (uri)........................................89
  4.3.5 job-name (name(MAX)).......................................89
  4.3.6 job-originating-user-name (name(MAX))......................89
  4.3.7 job-state (type1 enum).....................................89
   4.3.7.1  Partitioning of Job States............................92
  4.3.8 job-state-reasons (1setOf  type2 keyword)..................93

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  4.3.9 job-state-message (text(MAX))..............................95
  4.3.10    number-of-documents (integer(0:MAX))..................95
  4.3.11    output-device-assigned (name(127))....................96
  4.3.12    time-at-creation (integer(0:MAX)).....................96
  4.3.13    time-at-processing (integer(0:MAX))...................96
  4.3.14    time-at-completed (integer(0:MAX))....................96
  4.3.15    number-of-intervening-jobs (integer(0:MAX))...........96
  4.3.16    job-message-from-operator (text(127)).................96
  4.3.17    job-k-octets (integer(0:MAX)).........................97
  4.3.18    job-impressions (integer(0:MAX))......................97
  4.3.19    job-media-sheets (integer(0:MAX)).....................98
  4.3.20    job-k-octets-processed (integer(0:MAX))...............98
  4.3.21    job-impressions-completed (integer(0:MAX))............98
  4.3.22    job-media-sheets-completed (integer(0:MAX))...........99
  4.3.23    attributes-charset (charset)..........................99
  4.3.24    attributes-natural-language (naturalLanguage).........99
 4.4 Printer Description Attributes................................99
  4.4.1 printer-uri-supported (1setOf uri)........................101
  4.4.2 uri-security-supported (1setOf type2 keyword).............101
  4.4.3 printer-name (name(127))..................................102
  4.4.4 printer-location (text(127))..............................103
  4.4.5 printer-info (text(127))..................................103
  4.4.6 printer-more-info (uri)...................................103
  4.4.7 printer-driver-installer (uri)............................103
  4.4.8 printer-make-and-model (text(127))........................103
  4.4.9 printer-more-info-manufacturer (uri)......................103
  4.4.10    printer-state (type1 enum)...........................104
  4.4.11    printer-state-reasons (1setOf type2 keyword).........105
  4.4.12    printer-state-message (text(MAX))....................107
  4.4.13    operations-supported (1setOf type2 enum).............107
  4.4.14    charset-configured (charset).........................108
  4.4.15    charset-supported (1setOf charset)...................108
  4.4.16    natural-language-configured (naturalLanguage)........109
  4.4.17    generated-natural-language-supported (1setOf
  naturalLanguage)................................................109
  4.4.18    document-format-default (mimeMediaType)..............109
  4.4.19    document-format-supported (1setOf mimeMediaType).....110
  4.4.20    printer-is-accepting-jobs (boolean)..................110
  4.4.21    queued-job-count (integer(0:MAX))....................110
  4.4.22    printer-message-from-operator (text(127))............110
  4.4.23    color-supported (boolean)............................110
  4.4.24    reference-uri-schemes-supported (1setOf uriScheme)...110
  4.4.25    pdl-override-supported (type2 keyword)...............111
  4.4.26    printer-up-time (integer(1:MAX)).....................111
  4.4.27    printer-current-time (dateTime)......................112
  4.4.28    multiple-operation-time-out (integer(1:MAX)).........112
  4.4.29    compression-supported (1setOf type3 keyword).........112
  4.4.30    job-k-octets-supported (rangeOfInteger(0:MAX)).......112
  4.4.31    job-impressions-supported (rangeOfInteger(0:MAX))....113
  4.4.32    job-media-sheets-supported (rangeOfInteger(0:MAX))...113
  4.4.33    pages-per-minute (integer(0:MAX))....................113
  4.4.34    pages-per-minute-color (integer(0:MAX))..............113

5. Conformance....................................................114

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 5.1 Client Conformance Requirements..............................114
 5.2 IPP Object Conformance Requirements..........................115
  5.2.1 Objects...................................................115
  5.2.2 Operations................................................115
  5.2.3 IPP Object Attributes.....................................116
  5.2.4 Versions..................................................107
  5.2.5 Extensions................................................116
  5.2.6 Attribute Syntaxes........................................116
 5.3 Charset and Natural Language Requirements....................116
 5.4 Security Conformance Requirements............................117

6. IANA Considerations (registered and private extensions)........117
 6.1 Typed 'keyword' and 'enum' Extensions........................118
 6.2 Attribute Extensibility......................................120
 6.3 Attribute Syntax Extensibility...............................120
 6.4 Operation Extensibility......................................121
 6.5 Attribute Groups.............................................121
 6.6 Status Code Extensibility....................................121
 6.7 Registration of MIME types/sub-types for document-formats....122
 6.8 Registration of charsets for use in 'charset' attribute values122

7. Internationalization Considerations............................122

8. Security Considerations........................................125
 8.1 Security Scenarios...........................................126
  8.1.1 Client and Server in the Same Security Domain.............126
  8.1.2 Client and Server in Different Security Domains...........127
  8.1.3 Print by Reference........................................127
 8.2 URIs for TLS and non-TLS Access..............................127
 8.3 The "requesting-user-name" (name(MAX)) Operation Attribute...127
 8.4 Restricted Queries...........................................129
 8.5 Operations performed by operators and system administrators..129
 8.6 Queries on jobs submitted using non-IPP protocols............129
 8.7 IPP Security Application Profile for TLS.....................130

9. References.....................................................130

10.Notices.......................................................134

11.Author's Address..............................................135

12.Formats for IPP Registration Proposals........................137
 12.1.....................Type2 keyword attribute values registration
     137
 12.2.....................Type3 keyword attribute values registration
     137
 12.3........................Type2 enum attribute values registration
     137
 12.4........................Type3 enum attribute values registration
     138
 12.5..........................................Attribute registration
     138
 12.6...................................Attribute Syntax registration
     139

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 12.7..........................................Operation registration
     139
 12.8....................................Attribute Group registration
     139
 12.9........................................Status code registration
     140

13.APPENDIX A: Terminology.......................................140
 13.1.........................................Conformance Terminology
     140
  13.1.1    NEED NOT.............................................140
 13.2...............................................Model Terminology
     140
  13.2.1    Keyword..............................................140
  13.2.2    Attributes...........................................140
   13.2.2.1 Attribute Name.......................................141
   13.2.2.2 Attribute Group Name.................................141
   13.2.2.3 Attribute Value......................................141
   13.2.2.4 Attribute Syntax.....................................141
  13.2.3    Supports.............................................141
  13.2.4    print-stream page....................................143
  13.2.5    impression...........................................143

14.APPENDIX B:  Status Codes and Suggested Status Code Messages..143
 14.1....................................................Status Codes
     144
  14.1.1    Informational........................................145
  14.1.2    Successful Status Codes..............................145
   14.1.2.1 successful-ok (0x0000)...............................145
   14.1.2.2 successful-ok-ignored-or-substituted-attributes (0x0001)145
   14.1.2.3 successful-ok-conflicting-attributes (0x0002)........145
  14.1.3    Redirection Status Codes.............................146
  14.1.4    Client Error Status Codes............................146
   14.1.4.1 client-error-bad-request (0x0400)....................146
   14.1.4.2 client-error-forbidden (0x0401)......................146
   14.1.4.3 client-error-not-authenticated (0x0402)..............146
   14.1.4.4 client-error-not-authorized (0x0403).................146
   14.1.4.5 client-error-not-possible (0x0404)...................147
   14.1.4.6 client-error-timeout (0x0405)........................147
   14.1.4.7 client-error-not-found (0x0406)......................147
   14.1.4.8 client-error-gone (0x0407)...........................147
   14.1.4.9 client-error-request-entity-too-large (0x0408).......148
   14.1.4.10client-error-request-value-too-long (0x0409).........148
   14.1.4.11client-error-document-format-not-supported (0x040A)..148
   14.1.4.12client-error-attributes-or-values-not-supported (0x040B)148
   14.1.4.13client-error-uri-scheme-not-supported (0x040C).......149
   14.1.4.14client-error-charset-not-supported (0x040D)..........149
   14.1.4.15client-error-conflicting-attributes (0x040E).........149
  14.1.5    Server Error Status Codes............................149
   14.1.5.1 server-error-internal-error (0x0500).................149
   14.1.5.2 server-error-operation-not-supported (0x0501)........150
   14.1.5.3 server-error-service-unavailable (0x0502)............150
   14.1.5.4 server-error-version-not-supported (0x0503)..........150
   14.1.5.5 server-error-device-error (0x0504)...................150

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   14.1.5.6 server-error-temporary-error (0x0505)................151
   14.1.5.7 server-error-not-accepting-jobs (0x0506).............151
   14.1.5.8 server-error-busy (0x0507)...........................151
   14.1.5.9 server-error-job-canceled (0x0508)...................151
 14.2.................................Status Codes for IPP Operations
     152

15.APPENDIX C:  "media" keyword values...........................153

16.APPENDIX D: Processing IPP Attributes.........................158
 16.1........................................................Fidelity
     158
 16.2........................Page Description Language (PDL) Override
     159
 16.3.......Using Job Template Attributes During Document Processing.
     161

17.APPENDIX E: Generic Directory Schema..........................162

18.APPENDIX F:  Differences between the IPP/1.0 and IPP/1.1 "Model and
Semantics" Specifications.........................................164


































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1. Introduction


The Internet Printing Protocol (IPP) is an application level protocol
that can be used for distributed printing using Internet tools and
technologies.  IPP version 1.1 (IPP/1.1) focuses only on end user
functionality.  This document is just one of a suite of documents that
fully define IPP.  The full set of IPP documents includes:

  Design Goals for an Internet Printing Protocol [IPP-REQ]
  Rationale for the Structure and Model and Protocol for the Internet
     Printing Protocol [IPP-RAT]
  Internet Printing Protocol/1.1: Model and Semantics (this document)
  Internet Printing Protocol/1.1: Encoding and Transport [IPP-PRO]
  Internet Printing Protocol/1.1: Implementer's Guide [IPP-IIG]
  Mapping between LPD and IPP Protocols [IPP-LPD]


Anyone reading these documents for the first time is strongly encouraged
to read the IPP documents in the above order.

This document is laid out as follows:

  - The rest of Section 1 is an introduction to the IPP simplified
     model for distributed printing.
  - Section 2 introduces the object types covered in the model with
     their basic behaviors, attributes, and interactions.
  - Section 3 defines the operations included in IPP/1.1.  IPP
     operations are synchronous, therefore, for each operation, there is
     a both request and a response.
  - Section 4 defines the attributes (and their syntaxes) that are used
     in the model.
  - Sections 5 - 6 summarizes the implementation conformance
     requirements for objects that support the protocol and IANA
     considerations, respectively.
  - Sections 7 - 12 cover the Internationalization and Security
     considerations as well as References, Intellectual Property Notice,
     Copyright Notice, Author contact information, and Formats for
     Registration Proposals.
  - Sections 13 - 15 are appendices that cover Terminology, Status
     Codes and Messages, and "media" keyword values.

          Note: This document uses terms such as "attributes",
          "keywords", and "support".  These terms have special meaning
          and are defined in the model terminology section 13.2.
          Capitalized terms, such as MUST, MUST NOT, REQUIRED, SHOULD,
          SHOULD NOT, MAY, NEED NOT, and OPTIONAL, have special meaning
          relating to conformance.  These terms are defined in section
          13.1 on conformance terminology, most of which is taken from
          RFC 2119 [RFC2119].

  - Section 16 is an appendix that helps to clarify the effects of
     interactions between related attributes and their values.
  - Section 17 is an appendix that enumerates the subset of Printer
     attributes that form a generic directory schema.  These attributes
     are useful when registering a Printer so that a client can find the
     Printer not just by name, but by filtered searches as well.


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  - Section 18 is an appendix summarizing the additions and changes
     from the IPP/1.0 "Model and Semantics" specification [IPP-MOD1.0]
     to make this IPP/1.1 document.

1.1 Simplified Printing Model


In order to achieve its goal of realizing a workable printing protocol
for the Internet, the Internet Printing Protocol (IPP) is based on a
simplified printing model that abstracts the many components of real
world printing solutions.  The Internet is a distributed computing
environment where requesters of print services (clients, applications,
printer drivers, etc.) cooperate and interact with print service
providers.  This model and semantics document describes a simple,
abstract model for IPP even though the underlying configurations may be
complex "n-tier" client/server systems.  An important simplifying step
in the IPP model is to expose only the key objects and interfaces
required for printing.  The model described in this model document does
not include features, interfaces, and relationships that are beyond the
scope of the first version of IPP (IPP/1.1).  IPP/1.1 incorporates many
of the relevant ideas and lessons learned from other specification and
development efforts [HTPP] [ISO10175] [LDPA] [P1387.4] [PSIS] [RFC1179]
[SWP].  IPP is heavily influenced by the printing model introduced in
the Document Printing Application (DPA) [ISO10175] standard.  Although
DPA specifies both end user and administrative features, IPP version 1.1
(IPP/1.1) focuses primarily on end user functionality with a few
additional OPTIONAL operator operations.

The IPP/1.1 model encapsulates the important components of distributed
printing into two object types:

  - Printer (Section 2.1)
  - Job (Section 2.2)


Each object type has an associated set of operations (see section 3) and
attributes (see section 3.3.5).

It is important, however, to understand that in real system
implementations (which lie underneath the abstracted IPP/1.1 model),
there are other components of a print service which are not explicitly
defined in the IPP/1.1 model. The following figure illustrates where
IPP/1.1 fits with respect to these other components.














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                             +--------------+
                             |  Application |
                   o         +. . . . . . . |
                  \|/        |   Spooler    |
                  / \        +. . . . . . . |   +---------+
                End-User     | Print Driver |---|  File   |
      +-----------+ +-----+  +------+-------+   +----+----+
      |  Browser  | | GUI |         |                |
      +-----+-----+ +--+--+         |                |
            |          |            |                |
            |      +---+------------+---+            |
N   D   S   |      |      IPP Client    |------------+
O   I   E   |      +---------+----------+
T   R   C   |                |
I   E   U   |
F   C   R   -------------- Transport ------------------
I   T   I
C   O   T                    |         --+
A   R   Y           +--------+--------+  |
T   Y               |    IPP Server   |  |
I                   +--------+--------+  |
O                            |           |
N                   +-----------------+  | IPP Printer
                    |  Print Service  |  |
                    +-----------------+  |
                             |         --+
                    +-----------------+
                    | Output Device(s)|
                    +-----------------+


An IPP Printer object encapsulates the functions normally associated
with physical output devices along with the spooling, scheduling and
multiple device management functions often associated with a print
server. Printer objects are optionally registered as entries in a
directory where end users find and select them based on some sort of
filtered and context based searching mechanism (see section 17).  The
directory is used to store relatively static information about the
Printer, allowing end users to search for and find Printers that match
their search criteria, for example: name, context, printer capabilities,
etc.  The more dynamic information, such as state, currently loaded and
ready media, number of jobs at the Printer, errors, warnings, and so
forth, is directly associated with the Printer object itself rather than
with the entry in the directory which only represents the Printer
object.

IPP clients implement the IPP protocol on the client side and give end
users (or programs running on behalf of end users) the ability to query
Printer objects and submit and manage print jobs.  An IPP server is just
that part of the Printer object that implements the server-side
protocol.  The rest of the Printer object implements (or gateways into)
the application semantics of the print service itself.  The Printer



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objects may be embedded in an output device or may be implemented on a
host on the network that communicates with an output device.

When a job is submitted to the Printer object and the Printer object
validates the attributes in the submission request, the Printer object
creates a new Job object.  The end user then interacts with this new Job
object to query its status and monitor the progress of the job.  An end
user can also cancel their print jobs by using the Job object's Cancel-
Job operation.  An end-user can also hold, release, and restart their
print jobs using the Job object's OPTIONAL Hold-Job, Release-Job, and
Restart-Job operations, if implemented.

A privileged operator or administrator of a Printer object can cancel,
hold, release, and restart any user's job using the REQUIRED Cancel-Job
and the OPTIONAL Hold-Job, Release-Job, and Restart-Job operations.  In
additional privileged operator or administrator of a Printer object can
pause, resume, or purge (jobs from) a Printer object using the OPTIONAL
Pause-Printer, Resume-Printer, and Purge-Jobs operations, if
implemented.

The notification service is out of scope for this IPP/1.1 specification,
but using such a notification service, the end user is able to register
for and receive Printer specific and Job specific events.  An end user
can query the status of Printer objects and can follow the progress of
Job objects by polling using the Get-Printer-Attributes, Get-Jobs, and
Get-Job-Attributes operations.



2. IPP Objects


The IPP/1.1 model introduces objects of type Printer and Job.  Each type
of object models relevant aspects of a real-world entity such as a real
printer or real print job.  Each object type is defined as a set of
possible attributes that may be supported by instances of that object
type.  For each object (instance), the actual set of supported
attributes and values describe a specific implementation.  The object's
attributes and values describe its state, capabilities, realizable
features, job processing functions, and default behaviors and
characteristics.  For example, the Printer object type is defined as a
set of attributes that each Printer object potentially supports.  In the
same manner, the Job object type is defined as a set of attributes that
are potentially supported by each Job object.

Each attribute included in the set of attributes defining an object type
is labeled as:

  - "REQUIRED": each object MUST support the attribute.
  - "OPTIONAL": each object MAY support the attribute.


There is no such similar labeling of attribute values.  However, if an
implementation supports an attribute, it MUST support at least one of
the possible values for that attribute.


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2.1 Printer Object


The major component of the IPP/1.1 model is the Printer object.  A
Printer object implements the server-side of the IPP/1.1 protocol.
Using the protocol, end users may query the attributes of the Printer
object and submit print jobs to the Printer object.  The actual
implementation components behind the Printer abstraction may take on
different forms and different configurations.  However, the model
abstraction allows the details of the configuration of real components
to remain opaque to the end user.  Section 3 describes each of the
Printer operations in detail.

The capabilities and state of a Printer object are described by its
attributes.  Printer attributes are divided into two groups:

  - "job-template" attributes: These attributes describe supported job
     processing capabilities and defaults for the Printer object. (See
     section 4.2)
  - "printer-description" attributes: These attributes describe the
     Printer object's identification, state, location, references to
     other sources of information about the Printer object, etc. (see
     section 4.4)


Since a Printer object is an abstraction of a generic document output
device and print service provider, a Printer object could be used to
represent any real or virtual device with semantics consistent with the
Printer object, such as a fax device, an imager, or even a CD writer.

Some examples of configurations supporting a Printer object include:

  1) An output device with no spooling capabilities
  2) An output device with a built-in spooler
  3) A print server supporting IPP with one or more associated output
     devices
     3a) The associated output devices may or may not be capable of
       spooling jobs
     3b) The associated output devices may or may not support IPP


The following figures show some examples of how Printer objects can be
realized on top of various distributed printing configurations.  The
embedded case below represents configurations 1 and 2. The hosted and
fan-out figures below represent configurations 3a and 3b.













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Legend:

##### indicates a Printer object which is
      either embedded in an output device or is
      hosted in a server.  The Printer object
      might or might not be capable of queuing/spooling.

any   indicates any network protocol or direct
      connect, including IPP


embedded printer:
                                          output device
                                        +---------------+
 O   +--------+                         |  ###########  |
/|\  | client |------------IPP------------># Printer #  |
/ \  +--------+                         |  # Object  #  |
                                        |  ###########  |
                                        +---------------+


hosted printer:
                                        +---------------+
 O   +--------+        ###########      |               |
/|\  | client |--IPP--># Printer #-any->| output device |
/ \  +--------+        # Object  #      |               |
                       ###########      +---------------+



                                         +---------------+
fan out:                                 |               |
                                     +-->| output device |
                                 any/    |               |
 O   +--------+      ###########   /     +---------------+
/|\  | client |-IPP-># Printer #--*
/ \  +--------+      # Object  #   \     +---------------+
                     ########### any\    |               |
                                     +-->| output device |
                                         |               |
                                         +---------------+



2.2 Job Object


A Job object is used to model a print job.  A Job object contains
documents.  The information required to create a Job object is sent in a
create request from the end user via an IPP Client to the Printer
object.  The Printer object validates the create request, and if the
Printer object accepts the request, the Printer object creates the new
Job object.  Section 3 describes each of the Job operations in detail.



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The characteristics and state of a Job object are described by its
attributes.  Job attributes are grouped into two groups as follows:

  - "job-template" attributes: These attributes can be supplied by the
     client or end user and include job processing instructions which
     are intended to override any Printer object defaults and/or
     instructions embedded within the document data. (See section 4.2)
  - "job-description" attributes: These attributes describe the Job
     object's identification, state, size, etc. The client supplies some
     of these attributes, and the Printer object generates others. (See
     section 4.3)


An implementation MUST support at least one document per Job object.  An
implementation MAY support multiple documents per Job object.  A
document is either:

  - a stream of document data in a format supported by the Printer
     object (typically a Page Description Language - PDL), or
  - a reference to such a stream of document data


In IPP/1.1, a document is not modeled as an IPP object, therefore it has
no object identifier or associated attributes.  All job processing
instructions are modeled as Job object attributes.  These attributes are
called Job Template attributes and they apply equally to all documents
within a Job object.


2.3 Object Relationships


IPP objects have relationships that are maintained persistently along
with the persistent storage of the object attributes.

A Printer object can represent either one or more physical output
devices or a logical device which "processes" jobs but never actually
uses a physical output device to put marks on paper.  Examples of
logical devices include a Web page publisher or a gateway into an online
document archive or repository.  A Printer object contains zero or more
Job objects.

A Job object is contained by exactly one Printer object, however the
identical document data associated with a Job object could be sent to
either the same or a different Printer object.  In this case, a second
Job object would be created which would be almost identical to the first
Job object, however it would have new (different) Job object identifiers
(see section 2.4).

A Job object is either empty (before any documents have been added) or
contains one or more documents.  If the contained document is a stream
of document data, that stream can be contained in only one document.
However, there can be identical copies of the stream in other documents
in the same or different Job objects.  If the contained document is just
a reference to a stream of document data, other documents (in the same
or different Job object(s)) may contain the same reference.


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2.4 Object Identity


All Printer and Job objects are identified by a Uniform Resource
Identifier (URI) [RFC2396] so that they can be persistently and
unambiguously referenced.  The notion of a URI is a useful concept,
however, until the notion of URI is more stable (i.e., defined more
completely and deployed more widely), it is expected that the URIs used
for IPP objects will actually be URLs [RFC2396].  Since every URL is a
specialized form of a URI, even though the more generic term URI is used
throughout the rest of this document, its usage is intended to cover the
more specific notion of URL as well.

An administrator configures Printer objects to either support or not
support authentication and/or message privacy using TLS [TLS] (the
mechanism for security configuration is outside the scope of this
IPP/1.1 document).  In some situations, both types of connections (both
authenticated and unauthenticated) can be established using a single
communication channel that has some sort of negotiation mechanism.  In
other situations, multiple communication channels are used, one for each
type of security configuration.  Section 8 provides a full description
of all security considerations and configurations.

If a Printer object supports more than one communication channel, some
or all of those channels might support and/or require different security
mechanisms.  In such cases, an administrator could expose the
simultaneous support for these multiple communication channels as
multiple URIs for a single Printer object where each URI represents one
of the communication channels to the Printer object. To support this
flexibility, the IPP Printer object type defines a multi-valued
identification attribute called the "printer-uri-supported" attribute.
It MUST contain at least one URI.  It MAY contain more than one URI.
That is, every Printer object will have at least one URI that identifies
at least one communication channel to the Printer object, but it may
have more than one URI where each URI identifies a different
communication channel to the Printer object.  The "printer-uri-
supported" attribute has a companion attribute, the "uri-security-
supported" attribute, that has the same cardinality as "printer-uri-
supported".  The purpose of the "uri-security-supported" attribute is to
indicate the security mechanisms (if any) used for each URI listed in
"printer-uri-supported".  These two attributes are fully described in
sections 4.4.1 and 4.4.2.

When a job is submitted to the Printer object via a create request, the
client supplies only a single Printer object URI.  The client supplied
Printer object URI MUST be one of the values in the "printer-uri-
supported" Printer attribute.

Note:  IPP/1.1 does not specify how the client obtains the client
supplied URI, but it is RECOMMENDED that a Printer object be registered
as an entry in a directory service.  End-users and programs can then
interrogate the directory searching for Printers. Section 17 defines a
generic schema for Printer object entries in the directory service and
describes how the entry acts as a bridge to the actual IPP Printer


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object.  The entry in the directory that represents the IPP Printer
object includes the possibly many URIs for that Printer object as values
in one its attributes.

When a client submits a create request to the Printer object, the
Printer object validates the request and creates a new Job object.  The
Printer object assigns the new Job object a URI which is stored in the
"job-uri" Job attribute.  This URI is then used by clients as the target
for subsequent Job operations.  The Printer object generates a Job URI
based on its configured security policy and the URI used by the client
in the create request.

For example, consider a Printer object that supports both a
communication channel secured by the use of SSL3 (using HTTP over SSL3
with an "https" schemed URI) and another open communication channel that
is not secured with SSL3 (using a simple "http" schemed URI).  If a
client were to submit a job using the secure URI, the Printer object
would assign the new Job object a secure URI as well.  If a client were
to submit a job using the open-channel URI, the Printer would assign the
new Job object an open-channel URI.

In addition, the Printer object also populates the Job object's "job-
printer-uri" attribute.  This is a reference back to the Printer object
that created the Job object.  If a client only has access to a Job
object's "job-uri" identifier, the client can query the Job's "job-
printer-uri" attribute in order to determine which Printer object
created the Job object.  If the Printer object supports more than one
URI, the Printer object picks the one URI supplied by the client when
creating the job to build the value for and to populate the Job's "job-
printer-uri" attribute.

Allowing Job objects to have URIs allows for flexibility and
scalability.  For example, in some implementations, the Printer object
might create Jobs that are processed in the same local environment as
the Printer object itself.  In this case, the Job URI might just be a
composition of the Printer's URI and some unique component for the Job
object, such as the unique 32-bit positive integer mentioned later in
this paragraph.  In other implementations, the Printer object might be a
central clearing-house for validating all Job object creation requests,
but the Job object itself might be created in some environment that is
remote from the Printer object.  In this case, the Job object's URI may
have no physical-location relationship at all to the Printer object's
URI.  Again, the fact that Job objects have URIs allows for flexibility
and scalability, however, many existing printing systems have local
models or interface constraints that force print jobs to be identified
using only a 32-bit positive integer rather than an independent URI.
This numeric Job ID is only unique within the context of the Printer
object to which the create request was originally submitted.  Therefore,
in order to allow both types of client access to IPP Job objects (either
by Job URI or by numeric Job ID), when the Printer object successfully
processes a create request and creates a new Job object, the Printer
object MUST generate both a Job URI and a Job ID.  The Job ID (stored in
the "job-id" attribute) only has meaning in the context of the Printer
object to which the create request was originally submitted. This

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requirement to support both Job URIs and Job IDs allows all types of
clients to access Printer objects and Job objects no matter the local
constraints imposed on the client implementation.

In addition to identifiers, Printer objects and Job objects have names
("printer-name" and "job-name").  An object name NEED NOT be unique
across all instances of all objects. A Printer object's name is chosen
and set by an administrator through some mechanism outside the scope of
this IPP/1.1 document.  A Job object's name is optionally chosen and
supplied by the IPP client submitting the job.  If the client does not
supply a Job object name, the Printer object generates a name for the
new Job object.  In all cases, the name only has local meaning.

To summarize:

  - Each Printer object is identified with one or more URIs.  The
     Printer's "printer-uri-supported" attribute contains the URI(s).
  - The Printer object's "uri-security-supported" attribute identifies
     the communication channel security protocols that may or may not
     have been configured for the various Printer object URIs (e.g.,
     'tls' or 'none').
  - Each Job object is identified with a Job URI.  The Job's "job-uri"
     attribute contains the URI.
  - Each Job object is also identified with Job ID which is a 32-bit,
     positive integer.  The Job's "job-id" attribute contains the Job
     ID.  The Job ID is only unique within the context of the Printer
     object  which created the Job object.
  - Each Job object has a "job-printer-uri" attribute which contains
     the URI of the Printer object that was used to create the Job
     object.  This attribute is used to determine the Printer object
     that created a Job object when given only the URI for the Job
     object.  This linkage is necessary to determine the languages,
     charsets, and operations which are supported on that Job (the basis
     for such support comes from the creating Printer object).
  - Each Printer object has a name (which is not necessarily unique).
     The administrator chooses and sets this name through some mechanism
     outside the scope of this IPP/1.1 document.  The Printer object's
     "printer-name" attribute contains the name.
  - Each Job object has a name (which is not necessarily unique).  The
     client optionally supplies this name in the create request.  If the
     client does not supply this name, the Printer object generates a
     name for the Job object. The Job object's "job-name" attribute
     contains the name.


3. IPP Operations


IPP objects support operations.  An operation consists of a request and
a response.  When a client communicates with an IPP object, the client
issues an operation request to the URI for that object.  Operation
requests and responses have parameters that identify the operation.
Operations also have attributes that affect the run-time characteristics
of the operation (the intended target, localization information, etc.).
These operation-specific attributes are called operation attributes (as

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compared to object attributes such as Printer object attributes or Job
object attributes).  Each request carries along with it any operation
attributes, object attributes, and/or document data required to perform
the operation.  Each request requires a response from the object.  Each
response indicates success or failure of the operation with a status
code as a response parameter.  The response contains any operation
attributes, object attributes, and/or status messages generated during
the execution of the operation request.

This section describes the semantics of the IPP operations, both
requests and responses, in terms of the parameters, attributes, and
other data associated with each operation.

The IPP/1.1 Printer operations are:

  Print-Job (section 3.2.1)
  Print-URI (section 3.2.2)
  Validate-Job (section 3.2.3)
  Create-Job (section 3.2.4)
  Get-Printer-Attributes (section 3.2.5)
  Get-Jobs (section 3.2.6)
  Pause-Printer (section 3.3.5)
  Resume-Printer (section 3.3.6)
  Purge-Jobs (section 3.3.7)


The Job operations are:

  Send-Document (section 3.3.1)
  Send-URI (section 3.3.2)
  Cancel-Job (section 3.3.3)
  Get-Job-Attributes (section 3.3.4)
  Hold-Job (section 3.3.5)
  Release-Job (section 3.3.6)
  Restart-Job (section 3.3.7)


The Send-Document and Send-URI Job operations are used to add a new
document to an existing multi-document Job object created using the
Create-Job operation.


3.1 Common Semantics

All IPP operations require some common parameters and operation
attributes.  These common elements and their semantic characteristics
are defined and described in more detail in the following sections.

3.1.1 Required Parameters

Every operation request contains the following REQUIRED parameters:

  - a "version-number",
  - an "operation-id",
  - a "request-id", and
  - the attributes that are REQUIRED for that type of request.


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Every operation response contains the following REQUIRED parameters:

  - a "version-number",
  - a "status-code",
  - the "request-id" that was supplied in the corresponding request,
     and
  - the attributes that are REQUIRED for that type of response.

The "Encoding and Transport document [IPP-PRO] defines special rules for
the encoding of these parameters.  All other operation elements are
represented using the more generic encoding rules for attributes and
groups of attributes.

3.1.2 Operation IDs and Request IDs

Each IPP operation request includes an identifying "operation-id" value.
Valid values are defined in the "operations-supported" Printer attribute
section (see section 4.4.13).  The client specifies which operation is
being requested by supplying the correct "operation-id" value.

In addition, every invocation of an operation is identified by a
"request-id" value. For each request, the client chooses the "request-
id" which MUST be an integer (possibly unique depending on client
requirements) in the range from 1 to 2**31 - 1 (inclusive). This
"request-id" allows clients to manage multiple outstanding requests. The
receiving IPP object copies all 32-bits of the client-supplied "request-
id" attribute into the response so that the client can match the
response with the correct outstanding request, even if the "request-id"
is out of range.  If the request is terminated before the complete
"request-id" is received, the IPP object rejects the request and returns
a response with a "request-id" of 0.

Note: In some cases, the transport protocol underneath IPP might be a
connection oriented protocol that would make it impossible for a client
to receive responses in any order other than the order in which the
corresponding requests were sent.  In such cases, the "request-id"
attribute would not be essential for correct protocol operation.
However, in other mappings, the operation responses can come back in any
order.  In these cases, the "request-id" would be essential.


3.1.3 Attributes

Operation requests and responses are both composed of groups of
attributes and/or document data.  The attributes groups are:

  - Operation Attributes: These attributes are passed in the operation
     and affect the IPP object's behavior while processing the operation
     request and may affect other attributes or groups of attributes.
     Some operation attributes describe the document data associated
     with the print job and are associated with new Job objects, however
     most operation attributes do not persist beyond the life of the
     operation.  The description of each operation attribute includes
     conformance statements indicating which operation attributes are
     REQUIRED and which are OPTIONAL for an IPP object to support and


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     which attributes a client MUST supply in a request and an IPP
     object MUST supply in a response.
  - Job Template Attributes: These attributes affect the processing of
     a job.  A client OPTIONALLY supplies Job Template Attributes in a
     create request, and the receiving object MUST be prepared to
     receive all supported attributes.  The Job object can later be
     queried to find out what Job Template attributes were originally
     requested in the create request, and such attributes are returned
     in the response as Job Object Attributes.  The Printer object can
     be queried about its Job Template attributes to find out what type
     of job processing capabilities are supported and/or what the
     default job processing behaviors are, though such attributes are
     returned in the response as Printer Object Attributes.  The "ipp-
     attribute-fidelity" operation attribute affects processing of all
     client-supplied Job Template attributes (see sections 3.2.1.2 and
     16 for a full description of "ipp-attribute-fidelity" and its
     relationship to other attributes).
  - Job Object Attributes: These attributes are returned in response to
     a query operation directed at a Job object.
  - Printer Object Attributes: These attributes are returned in
     response to a query operation directed at a Printer object.
  - Unsupported Attributes: In a create request, the client supplies a
     set of Operation and Job Template attributes.  If any of these
     attributes or their values is unsupported by the Printer object,
     the Printer object returns the set of unsupported attributes in the
     response.  Sections 3.2.1.2 and  16 give a full description of how
     Job Template attributes supplied by the client in a create request
     are processed by the Printer object and how unsupported attributes
     are returned to the client.  Because of extensibility, any IPP
     object might receive a request that contains new or unknown
     attributes or values for which it has no support. In such cases,
     the IPP object processes what it can and returns the unsupported
     attributes in the response.


Later in this section, each operation is formally defined by identifying
the allowed and expected groups of attributes for each request and
response.  The model identifies a specific order for each group in each
request or response, but the attributes within each group may be in any
order, unless specified otherwise.

Each attribute specification includes the attribute's name followed by
the name of its attribute syntax(es) in parenthesizes.  In addition,
each 'integer' attribute is followed by the allowed range in
parentheses, (m:n), for values of that attribute.  Each 'text' or 'name'
attribute is followed by the maximum size in octets in parentheses,
(size), for values of that attribute. For more details on attribute
syntax notation, see the descriptions of these attributes syntaxes in
section 4.1.

Note: Document data included in the operation is not strictly an
attribute, but it is treated as a special attribute group for ordering
purposes.  The only operations that support supplying the document data



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within an operation request are Print-Job and Send-Document.  There are
no operation responses that include document data.

Note: Some operations are REQUIRED for IPP objects to support; the
others are OPTIONAL (see section 5.2.2).  Therefore, before using an
OPTIONAL operation, a client SHOULD first use the REQUIRED Get-Printer-
Attributes operation to query the Printer's "operations-supported"
attribute in order to determine which OPTIONAL Printer and Job
operations are actually supported.  The client SHOULD NOT use an
OPTIONAL operation that is not supported.  When an IPP object receives a
request to perform an operation it does not support, it returns the
'server-error-operation-not-supported' status code (see section
14.1.5.2).  An IPP object is non-conformant if it does not support a
REQUIRED operation.


3.1.4 Character Set and Natural Language Operation Attributes

Some Job and Printer attributes have values that are text strings and
names intended for human understanding rather than machine understanding
(see the 'text' and 'name' attribute syntax descriptions in section
4.1).  The following sections describe two special Operation Attributes
called "attributes-charset" and "attributes-natural-language".  These
attributes are always part of the Operation Attributes group.  For most
attribute groups, the order of the attributes within the group is not
important.  However, for these two attributes within the Operation
Attributes group, the order is critical.  The "attributes-charset"
attribute MUST be the first attribute in the group and the "attributes-
natural-language" attribute MUST be the second attribute in the group.
In other words, these attributes MUST be supplied in every IPP request
and response, they MUST come first in the group, and MUST come in the
specified order.  For job creation operations, the IPP Printer
implementation saves these two attributes with the new Job object as Job
Description attributes.  For the sake of brevity in this document, these
operation attribute descriptions are not repeated with every operation
request and response, but have a reference back to this section instead.


3.1.4.1 Request Operation Attributes

The client MUST supply and the Printer object MUST support the following
REQUIRED operation attributes in every IPP/1.1 operation request:

  "attributes-charset" (charset):
     This operation attribute identifies the charset (coded character
     set and encoding method) used by any 'text' and 'name' attributes
     that the client is supplying in this request.  It also identifies
     the charset that the Printer object MUST use (if supported) for all
     'text' and 'name' attributes and status messages that the Printer
     object returns in the response to this request. See Sections 4.1.1
     and 4.1.2 for the specification of the 'text' and 'name' attribute
     syntaxes.

     All clients and IPP objects MUST support the 'utf-8' charset
     [RFC2279] and MAY support additional charsets provided that they


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     are registered with IANA [IANA-CS].  If the Printer object does not
     support the client supplied charset value, the Printer object MUST
     reject the request, set the "attributes-charset" to 'utf-8' in the
     response, and return the 'client-error-charset-not-supported'
     status code and any 'text' or 'name' attributes using the 'utf-8'
     charset.  The Printer object MUST indicate the charset(s) supported
     as the values of the "charset-supported" Printer attribute (see
     Section 4.4.15), so that the client can query to determine which
     charset(s) are supported.

     Note to client implementers: Since IPP objects are only required to
     support the 'utf-8' charset, in order to maximize interoperability
     with multiple IPP object implementations, a client may want to
     supply 'utf-8' in the "attributes-charset" operation attribute,
     even though the client is only passing and able to present a
     simpler charset, such as US-ASCII or ISO-8859-1.  Then the client
     will have to filter out (or charset convert) those characters that
     are returned in the response that it cannot present to its user.
     On the other hand, if both the client and the IPP objects also
     support a charset in common besides utf-8, the client may want to
     use that charset in order to avoid charset conversion or data loss.

     See the 'charset' attribute syntax description in Section 4.1.7 for
     the syntax and semantic interpretation of the values of this
     attribute and for example values.

  "attributes-natural-language" (naturalLanguage):
     This operation attribute identifies the natural language used by
     any 'text' and 'name' attributes that the client is supplying in
     this request.  This attribute also identifies the natural language
     that the Printer object SHOULD use for all 'text' and 'name'
     attributes and status messages that the Printer object returns in
     the response to this request.

     There are no REQUIRED natural languages required for the Printer
     object to support.  However, the Printer object's "generated-
     natural-language-supported" attribute identifies the natural
     languages supported by the Printer object and any contained Job
     objects for all text strings generated by the IPP object.  A client
     MAY query this attribute to determine which natural language(s) are
     supported for generated messages.

     For any of the attributes for which the Printer object generates
     text, i.e., for the "job-state-message", "printer-state-message",
     and status messages (see Section 3.1.6), the Printer object MUST be
     able to generate these text strings in any of its supported natural
     languages.  If the client requests a natural language that is not
     supported, the Printer object MUST return these generated messages
     in the Printer's configured natural language as specified by the
     Printer's "natural-language-configured" attribute" (see Section
     4.4.16).

     For other 'text' and 'name' attributes supplied by the client,
     authentication system, operator, system administrator, or

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     manufacturer (i.e., for "job-originating-user-name", "printer-name"
     (name), "printer-location" (text), "printer-info" (text), and
     "printer-make-and-model" (text)), the Printer object is only
     required to support the configured natural language of the Printer
     identified by the Printer object's "natural-language-configured"
     attribute, though support of additional natural languages for these
     attributes is permitted.

     For any 'text' or 'name' attribute in the request that is in a
     different natural language than the value supplied in the
     "attributes-natural-language" operation attribute, the client MUST
     use the Natural Language Override mechanism (see sections 4.1.1.2
     and 4.1.2.2) for each such attribute value supplied.  The client
     MAY use the Natural Language Override mechanism redundantly, i.e.,
     use it even when the value is in the same natural language as the
     value supplied in the "attributes-natural-language" operation
     attribute of the request.

     The IPP object MUST accept any natural language and any Natural
     Language Override, whether the IPP object supports that natural
     language or not (and independent of the value of the "ipp-
     attribute-fidelity" Operation attribute).  That is the IPP object
     accepts all client supplied values no matter what the values are in
     the Printer object's "generated-natural-language-supported"
     attribute.  That attribute, "generated-natural-language-supported",
     only applies to generated messages, not client supplied messages.
     The IPP object MUST remember that natural language for all client-
     supplied attributes, and when returning those attributes in
     response to a query, the IPP object MUST indicate that natural
     language.

     Each value whose attribute syntax type is .text. or .name. (see
     sections 4.1.1 and 4.1.2) has an Associated Natural-Language.  This
     document does not specify how this association is stored in a
     Printer or Job object.  When such a value is encoded in a request
     or response, the natural language is either implicit or explicit:

          @ In the implicit case, the value contains only the text/name
            value, and the language is specified by the .attributes-
            natural-language. operation attribute in the request or
            response (see sections 4.1.1.1 textWithoutLanguage and
            4.1.2.1 nameWithoutLanguage).

          @ In the explicit case (also known as the Natural-Language
            Override case), the value contains both the language and
            the text/name value (see sections 4.1.1.2 textWithLanguage
            and 4.1.2.2 nameWithLanguage).

     For example, the "job-name" attribute MAY be supplied by the client
     in a create request.  The text value for this attribute will be in
     the natural language identified by the "attribute-natural-language"
     attribute, or if different, as identified by the Natural Language
     Override mechanism.  If supplied, the IPP object will use the value
     of the "job-name" attribute to populate the Job object's "job-name"

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     attribute.  Whenever any client queries the Job object's "job-name"
     attribute, the IPP object returns the attribute as stored and uses
     the Natural Language Override mechanism to specify the natural
     language, if it is different from that reported in the "attributes-
     natural-language" operation attribute of the response.  The IPP
     object MAY use the Natural Language Override mechanism redundantly,
     i.e., use it even when the value is in the same natural language
     as the value supplied in the "attributes-natural-language"
     operation attribute of the response.

     An IPP object MUST NOT reject a request based on a supplied natural
     language in an "attributes-natural-language" Operation attribute or
     in any attribute that uses the Natural Language Override.

     See the 'naturalLanguage' attribute syntax description in section
     4.1.8 for the syntax and semantic interpretation of the values of
     this attribute and for example values.


Clients SHOULD NOT supply 'text' or 'name' attributes that use an
illegal combination of natural language and charset.  For example,
suppose a Printer object supports charsets 'utf-8', 'iso-8859-1', and
'iso-8859-7'.  Suppose also, that it supports natural languages 'en'
(English), 'fr' (French), and 'el' (Greek).  Although the Printer object
supports the charset 'iso-8859-1' and natural language 'el', it probably
does not support the combination of Greek text strings using the 'iso-
8859-1' charset.  The Printer object handles this apparent
incompatibility differently depending on the context in which it occurs:

  - In a create request: If the client supplies a text or name
     attribute (for example, the "job-name" operation attribute) that
     uses an apparently incompatible combination, it is a client choice
     that does not affect the Printer object or its correct operation.
     Therefore, the Printer object simply accepts the client supplied
     value, stores it with the Job object, and responds back with the
     same combination whenever the client (or any client) queries for
     that attribute.
  -In a query-type operation, like Get-Printer-Attributes: If the
     client requests an apparently incompatible combination, the Printer
     object responds (as described in section 3.1.4.2) using the
     Printer's configured natural language rather than the natural
     language requested by the client.


In either case, the Printer object does not reject the request because
of the apparent incompatibility.  The potential incompatible combination
of charset and natural language can occur either at the global operation
level or at the Natural Language Override attribute-by-attribute level.
In addition, since the response always includes explicit charset and
natural language information, there is never any question or ambiguity
in how the client interprets the response.






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3.1.4.2 Response Operation Attributes

The Printer object MUST supply and the client MUST support the following
REQUIRED operation attributes in every IPP/1.1 operation response:

  "attributes-charset" (charset):
     This operation attribute identifies the charset used by any 'text'
     and 'name' attributes that the Printer object is returning in this
     response.  The value in this response MUST be the same value as the
     "attributes-charset" operation attribute supplied by the client in
     the request.  If this is not possible (i.e., the charset requested
     is not supported), the request would have been rejected.  See
     "attributes-charset" described in Section 3.1.4.1 above.

     If the Printer object supports more than just the 'utf-8' charset,
     the Printer object MUST be able to code convert between each of the
     charsets supported on a highest fidelity possible basis in order to
     return the 'text' and 'name' attributes in the charset requested by
     the client.  However, some information loss MAY occur during the
     charset conversion depending on the charsets involved.  For
     example, the Printer object may convert from a UTF-8 'a' to a US-
     ASCII 'a' (with no loss of information), from an ISO Latin 1
     CAPITAL LETTER A WITH ACUTE ACCENT to US-ASCII 'A' (losing the
     accent), or from a UTF-8 Japanese Kanji character to some ISO Latin
     1 error character indication such as '?', decimal code equivalent,
     or to the absence of a character, depending on implementation.

     Note: Whether an implementation that supports more than one charset
     stores the data in the charset supplied by the client or code
     converts to one of the other supported charsets, depends on
     implementation.  The strategy should try to minimize loss of
     information during code conversion.  On each response, such an
     implementation converts from its internal charset to that
     requested.

  "attributes-natural-language" (naturalLanguage):
     This operation attribute identifies the natural language used by
     any 'text' and 'name' attributes that the IPP object is returning
     in this response.  Unlike the "attributes-charset" operation
     attribute, the IPP object NEED NOT return the same value as that
     supplied by the client in the request.  The IPP object MAY return
     the natural language of the Job object or the Printer's configured
     natural language as identified by the Printer object's "natural-
     language-configured" attribute, rather than the natural language
     supplied by the client.  For any 'text' or 'name' attribute or
     status message in the response that is in a different natural
     language than the value returned in the "attributes-natural-
     language" operation attribute, the IPP object MUST use the Natural
     Language Override mechanism (see sections 4.1.1.2 and 4.1.2.2) on
     each attribute value returned.  The IPP object MAY use the Natural
     Language Override mechanism redundantly, i.e., use it even when the
     value is in the same natural language as the value supplied in the
     "attributes-natural-language" operation attribute of the response.



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3.1.5 Operation Targets

All IPP operations are directed at IPP objects.  For Printer operations,
the operation is always directed at a Printer object using one of its
URIs (i.e., one of the values in the Printer object's "printer-uri-
supported" attribute).  Even if the Printer object supports more than
one URI, the client supplies only one URI as the target of the
operation.  The client identifies the target object by supplying the
correct URI in the "printer-uri (uri)" operation attribute.

For Job operations, the operation is directed at either:

  - The Job object itself using the Job object's URI.  In this case,
     the client identifies the target object by supplying the correct
     URI in the "job-uri (uri)" operation attribute.
  - The Printer object that created the Job object using both the
     Printer objects URI and the Job object's Job ID.  Since the Printer
     object that created the Job object generated the Job ID, it MUST be
     able to correctly associate the client supplied Job ID with the
     correct Job object.  The client supplies the Printer object's URI
     in the "printer-uri (uri)" operation attribute and the Job object's
     Job ID in the "job-id (integer(1:MAX))" operation attribute.


If the operation is directed at the Job object directly using the Job
object's URI, the client MUST NOT include the redundant "job-id"
operation attribute.

The operation target attributes are REQUIRED operation attributes that
MUST be included in every operation request.  Like the charset and
natural language attributes (see section 3.1.4), the operation target
attributes are specially ordered operation attributes.  In all cases,
the operation target attributes immediately follow the "attributes-
charset" and "attributes-natural-language" attributes within the
operation attribute group, however the specific ordering rules are:

  - In the case where there is only one operation target attribute
     (i.e., either only the "printer-uri" attribute or only the "job-
     uri" attribute), that attribute MUST be the third attribute in the
     operation attributes group.
  - In the case where Job operations use two operation target
     attributes (i.e., the "printer-uri" and "job-id" attributes), the
     "printer-uri" attribute MUST be the third attribute and the "job-
     id" attribute MUST be the fourth attribute.


In all cases, the target URIs contained within the body of IPP operation
requests and responses must be in absolute format rather than relative
format (a relative URL identifies a resource with the scope of the HTTP
server, but does not include scheme, host or port).

The following rules apply to the use of port numbers in URIs that
identify IPP objects:

  1. If the URI scheme allows the port number to be explicitly included
     in the URI string, and a port number is specified within the URI,


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     then that port number MUST be used by the client to contact the IPP
     object.

  2. If the URI scheme allows the port number to be explicitly included
     in the URI string, and a port number is not specified within the
     URI, then default port number implied by that URI scheme MUST be
     used by the client to contact the IPP object.

  3. If the URI scheme does not allow an explicit port number to be
     specified within the URI, then the default port number implied by
     that URI MUST be used by the client to contact the IPP object.


Note: The IPP "Encoding and Transport document [IPP-PRO] shows a mapping
of IPP onto HTTP/1.1 and defines a new default port number for using IPP
over HTTP/1.1.


3.1.6 Operation Status Codes and Messages

Every operation response includes a REQUIRED "status-code" parameter and
an OPTIONAL "status-message" operation attribute.  The "status-code"
provides information on the processing of a request.  A "status-message"
attribute provides a short textual description of the status of the
operation.  The status code is intended for use by automata, and the
status message is intended for the human end user.  If a response does
include a "status-message" attribute, an IPP client NEED NOT examine or
display the message, however it SHOULD do so in some implementation
specific manner.

The "status-code" value is a numeric value that has semantic meaning.
The "status-code" syntax is similar to a "type2 enum" (see section 4.1
on "Attribute Syntaxes") except that values can range only from 0x0000
to 0x7FFF.  Section 14 describes the status codes, assigns the numeric
values, and suggests a corresponding status message for each status
code.  The "status-message" attribute's syntax is "text(255)".  A client
implementation of IPP SHOULD convert status code values into any
localized message that has semantic meaning to the end user.

If the Printer object supports the "status-message" operation attribute,
the Printer object MUST be able to generate this message in any of the
natural languages identified by the Printer object's "generated-natural-
language-supported" attribute (see the "attributes-natural-language"
operation attribute specified in section 3.1.4.1).  As described in
section 3.1.4.1 for any returned 'text' attribute, if there is a choice
for generating this message, the Printer object uses the natural
language indicated by the value of the "attributes-natural-language" in
the client request if supported, otherwise the Printer object uses the
value in the Printer object's own "natural-language-configured"
attribute.  If the Printer object supports the "status-message"
operation attribute, it SHOULD use the REQUIRED 'utf-8' charset to
return a status message for the following error status codes (see
section 14):  'client-error-bad-request', 'client-error-charset-not-
supported', 'server-error-internal-error', 'server-error-operation-not-
supported', and 'server-error-version-not-supported'.  In this case, it

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MUST set the value of the "attributes-charset" operation attribute to
'utf-8' in the error response.


3.1.7 Versions

Each operation request and response carries with it a "version-number"
parameter.  Each value of the "version-number" is in the form "X.Y"
where X is the major version number and Y is the minor version number.
By including a version number in the client request, it allows the
client  to identify which version of IPP it is interested in using.  If
the IPP object does not support that version, the object responds with a
status code of 'server-error-version-not-supported' along with the
closest version number that is supported (see section 14.1.5.4).

There is no version negotiation per se.  However, if after receiving a
'server-error-version-not-supported' status code from an IPP object,
there is nothing that prevents a client from trying again with a
different version number. In order to conform to IPP/1.1, an IPP object
implementations MUST support  versions '1.1' and 1.0.

There is only one notion of "version number" that covers both IPP Model
and IPP Protocol changes. Thus the version number MUST change when
introducing a new version of the Model and Semantics document [IPP-MOD]
or a new version of the "Encoding and Transport" document [IPP-PRO].

Changes to the major version number indicate structural or syntactic
changes that make it impossible for older version of IPP clients and
Printer objects to correctly parse and process the new or changed
attributes, operations and responses.  If the major version number
changes, the minor version numbers is set to zero.  As an example,
adding the "ipp-attribute-fidelity" attribute (if it had not been part
of version '1.1'), would have required a change to the major version
number.  Items that might affect the changing of the major version
number include any changes to the Model and Semantics document [IPP-MOD]
or the "Encoding and Transport" document [IPP-PRO] itself, such as:

  - reordering of ordered attributes or attribute sets
  - changes to the syntax of existing attributes
  - changing Operation or Job Template attributes from OPTIONAL to
     REQUIRED and vice versa
  - adding REQUIRED (for an IPP object to support) operation attributes
  - adding REQUIRED (for an IPP object to support) operation attribute
     groups
  - adding values to existing operation attributes
  - adding REQUIRED operations


Changes to the minor version number indicate the addition of new
features, attributes and attribute values that may not be understood by
all IPP objects, but which can be ignored if not understood.  Items that
might affect the changing of the minor version number include any
changes to the model objects and attributes but not the encoding and
transport rules [IPP-PRO] (except adding attribute syntaxes).  Examples
of such changes are:


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  - grouping all extensions not included in a previous version into a
     new version
  - adding new attribute values
  - adding new object attributes
  - adding OPTIONAL (for an IPP object to support) operation attributes
     (i.e., those attributes that an IPP object can ignore without
     confusing clients)
  - adding OPTIONAL (for an IPP object to support) operation attribute
     groups (i.e., those attributes that an IPP object can ignore
     without confusing clients)
  - adding new attribute syntaxes
  - adding OPTIONAL operations
  - changing Job Description attributes or Printer Description
     attributes from OPTIONAL to REQUIRED or vice versa.


The encoding of the "version-number" MUST NOT change over any version
number (either major or minor).  This rule guarantees that all future
versions will be backwards compatible with all previous versions (at
least for checking the "version-number").  In addition, any protocol
elements (attributes, error codes, tags, etc.) that are not carried
forward from one version to the next are deprecated so that they can
never be reused with new semantics.

Implementations that support a certain major version NEED NOT support
ALL previous versions.  As each new major version is defined (through
the release of a new specification), that major version will specify
which previous major versions MUST be supported in compliant
implementations.


3.1.8 Job Creation Operations

In order to "submit a print job" and create a new Job object, a client
issues a create request.  A create request is any one of following three
operation requests:

  - The Print-Job Request: A client that wants to submit a print job
     with only a single document uses the Print-Job operation.  The
     operation allows for the client to "push" the document data to the
     Printer object by including the document data in the request
     itself.

  - The Print-URI Request: A client that wants to submit a print job
     with only a single document (where the Printer object "pulls" the
     document data instead of the client "pushing" the data to the
     Printer object) uses the Print-URI operation.   In this case, the
     client includes in the request only a URI reference to the document
     data (not the document data itself).

  - The Create-Job Request: A client that wants to submit a print job
     with multiple documents uses the Create-Job operation.  This
     operation is followed by an arbitrary number of Send-Document
     and/or Send-URI operations (each creating another document for the
     newly create Job object).  The Send-Document operation includes the


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     document data in the request (the client "pushes" the document data
     to the printer), and the Send-URI operation includes only a URI
     reference to the document data in the request (the Printer "pulls"
     the document data from the referenced location).  The last Send-
     Document or Send-URI request for a given Job object includes a
     "last-document" operation attribute set to 'true' indicating that
     this is the last request.


Throughout this model specification, the term "create request" is used
to refer to any of these three operation requests.

A Create-Job operation followed by only one Send-Document operation is
semantically equivalent to a Print-Job operation, however, for
performance reasons, the client SHOULD use the Print-Job operation for
all single document jobs.  Also, Print-Job is a REQUIRED operation (all
implementations MUST support it) whereas Create-Job is an OPTIONAL
operation, hence some implementations might not support it.

Job submission time is the point in time when a client issues a create
request.  The initial state of every Job object is the 'pending' or
'pending-held' state.  Later, the Printer object begins processing the
print job.  At this point in time, the Job object's state moves to
'processing'.  This is known as job processing time.  There are
validation checks that must be done at job submission time and others
that must be performed at job processing time.

At job submission time and at the time a Validate-Job operation is
received, the Printer MUST do the following:

  1. Process the client supplied attributes and either accept or reject
     the request
  2. Validate the syntax of and support for the scheme of any client
     supplied URI


At job submission time the Printer object MUST validate whether or not
the supplied attributes, attribute syntaxes, and values are supported by
matching them with the Printer object's corresponding "xxx-supported"
attributes.  See section 3.2.1.2 for details.  [IPP-IIG] presents
suggested steps for an IPP object to either accept or reject any request
and additional steps for processing create requests.

At job submission time the Printer object NEED NOT perform the
validation checks reserved for job processing time such as:

  1. Validating the document data
  2. Validating the actual contents of any client supplied URI (resolve
     the reference and follow the link to the document data)


At job submission time, these additional job processing time validation
checks are essentially useless, since they require actually parsing and
interpreting the document data, are not guaranteed to be 100% accurate,
and MUST be done, yet again, at job processing time.  Also, in the case
of a URI, checking for availability at job submission time does not


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guarantee availability at job processing time.   In addition, at job
processing time, the Printer object might discover any of the following
conditions that were not detectable at job submission time:

  - runtime errors in the document data,
  - nested document data that is in an unsupported format,
  - the URI reference is no longer valid (i.e., the server hosting the
     document might be down), or
  - any other job processing error


At job processing time, since the Printer object has already responded
with a successful status code in the response to the create request, if
the Printer object detects an error, the Printer object is unable to
inform the end user of the error with an operation status code.   In
this case, the Printer, depending on the error, can set the "job-state",
"job-state-reasons", or "job-state-message" attributes to the
appropriate value(s) so that later queries can report the correct job
status.

Note: Asynchronous notification of events is outside the scope of this
IPP/1.1 document.


3.2 Printer Operations


All Printer operations are directed at Printer objects.  A client MUST
always supply the "printer-uri" operation attribute in order to identify
the correct target of the operation.


3.2.1 Print-Job Operation

This REQUIRED operation allows a client to submit a print job with only
one document and supply the document data (rather than just a reference
to the data).  See Section 16 for the suggested steps for processing
create operations and their Operation and Job Template attributes.


3.2.1.1 Print-Job Request

The following groups of attributes are supplied as part of the Print-Job
Request:

Group 1: Operation Attributes

  Natural Language and Character Set:
     The "attributes-charset" and "attributes-natural-language"
     attributes as described in section 3.1.4.1.  The Printer object
     MUST copy these values to the corresponding Job Description
     attributes described in sections 4.3.23 and 4.3.24.

  Target:
     The "printer-uri" (uri) operation attribute which is the target for
     this operation as described in section 3.1.5.



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  Requesting User Name:
     The "requesting-user-name" (name(MAX)) attribute SHOULD be supplied
     by the client as described in section 8.3.

  "job-name" (name(MAX)):
     The client OPTIONALLY supplies this attribute.  The Printer object
     MUST support this attribute.  It contains the client supplied Job
     name.  If this attribute is supplied by the client, its value is
     used for the "job-name" attribute of the newly created Job object.
     The client MAY automatically include any information that will help
     the end-user distinguish amongst his/her jobs, such as the name of
     the application program along with information from the document,
     such as the document name, document subject, or source file name.
     If this attribute is not supplied by the client, the Printer
     generates a name to use in the "job-name" attribute of the newly
     created Job object (see Section 4.3.5).

  "ipp-attribute-fidelity" (boolean):
     The client OPTIONALLY supplies this attribute.  The Printer object
     MUST support this attribute.  The value 'true' indicates that total
     fidelity to client supplied Job Template attributes and values is
     required, else the Printer object MUST reject the Print-Job
     request.  The value 'false' indicates that a reasonable attempt to
     print the Job object is acceptable and the Printer object MUST
     accept the Print-job request. If not supplied, the Printer object
     assumes the value is 'false'.  All Printer objects MUST support
     both types of job processing.  See section 16 for a full
     description of "ipp-attribute-fidelity" and its relationship to
     other attributes, especially the Printer object's "pdl-override-
     supported" attribute.

  "document-name" (name(MAX)):
     The client OPTIONALLY supplies this attribute.  The Printer object
     MUST support this attribute.   It contains the client supplied
     document name.  The document name MAY be different than the Job
     name.  Typically, the client software automatically supplies the
     document name on behalf of the end user by using a file name or an
     application generated name.  If this attribute is supplied, its
     value can be used in a manner defined by each implementation.
     Examples include: printed along with the Job (job start sheet, page
     adornments, etc.), used by accounting or resource tracking
     management tools, or even stored along with the document as a
     document level attribute.  IPP/1.1 does not support the concept of
     document level attributes.

  "document-format" (mimeMediaType) :
     The client OPTIONALLY supplies this attribute.  The Printer object
     MUST support this attribute.  The value of this attribute
     identifies the format of the supplied document data.  If the client
     does not supply this attribute, the Printer object assumes that the
     document data is in the format defined by the Printer object's
     "document-format-default" attribute.  If the client supplies this
     attribute, but the value is not supported by the Printer object,
     i.e., the value is not one of the values of the Printer object's

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     "document-format-supported" attribute, the Printer object MUST
     reject the request and return the 'client-error-document-format-
     not-supported' status code.

  "document-natural-language" (naturalLanguage):
     The client OPTIONALLY supplies this attribute.  The Printer object
     OPTIONALLY supports this attribute. This attribute specifies the
     natural language of the document for those document-formats that
     require a specification of the natural language in order to image
     the document unambiguously. There are no particular values required
     for the Printer object to support.

  "compression" (type3 keyword)
     The client OPTIONALLY supplies this attribute.  The Printer object
     OPTIONALLY supports this attribute and the "compression-supported"
     attribute (see section 4.4.29).  The client supplied "compression"
     operation attribute identifies the compression algorithm used on
     the document data.  If the client omits this attribute, the Printer
     object MUST assume that the data is not compressed.  If the client
     supplies the attribute and the Printer object supports the
     attribute, the Printer object uses the corresponding decompression
     algorithm on the document data.  If the client supplies this
     attribute, but the value is not supported by the Printer object,
     i.e., the value is not one of the values of the Printer object's
     "compression-supported" attribute, the Printer object MUST copy the
     attribute and its value to the Unsupported Attributes response
     group, reject the request, and return the 'client-error-attributes-
     or-values-not-supported' status code.  If the client supplies this
     attribute, but this attribute is not supported by the Printer
     object, i.e., the "compression-supported" attribute is not one of
     the Printer's Printer Description attributes, the Printer object
     MUST copy the attribute to the Unsupported Attributes response
     group changing the value to the out-of-band 'unsupported' value
     (see section 4.1), reject the request, and return the 'client-
     error-attributes-or-values-not-supported' status code.  See section
     3.2.1.2 for returning unsupported attributes and values.

  "job-k-octets" (integer(0:MAX))
     The client OPTIONALLY supplies this attribute.  The Printer object
     OPTIONALLY supports this attribute and the "job-k-octets-supported"
     attribute (see section 4.4.30).  The client supplied "job-k-octets"
     operation attribute identifies the total size of the document(s) in
     K octets being submitted (see section 4.3.17 for the complete
     semantics).  If the client supplies the attribute and the Printer
     object supports the attribute, the value of the attribute is used
     to populate the Job object's "job-k-octets" Job Description
     attribute.

     Note:  For this attribute and the following two attributes ("job-
     impressions", and "job-media-sheets"), if the client supplies the
     attribute, but the Printer object does not support the attribute,
     the Printer object ignores the client-supplied value.  If the
     client supplies the attribute and the Printer supports the
     attribute, and the value is within the range of the corresponding

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     Printer object's "xxx-supported" attribute, the Printer object MUST
     use the value to populate the Job object's "xxx" attribute.  If the
     client supplies the attribute and the Printer supports the
     attribute, but the value is outside the range of the corresponding
     Printer object's "xxx-supported" attribute, the Printer object MUST
     copy the attribute and its value to the Unsupported Attributes
     response group, reject the request, and return the 'client-error-
     attributes-or-values-not-supported' status code.  If the client
     does not supply the attribute, the Printer object MAY choose to
     populate the corresponding Job object attribute depending on
     whether the Printer object supports the attribute and is able to
     calculate or discern the correct value.

  "job-impressions" (integer(0:MAX))
     The client OPTIONALLY supplies this attribute.  The Printer object
     OPTIONALLY supports this attribute and the "job-impressions-
     supported" attribute (see section 4.4.31).  The client supplied
     "job-impressions" operation attribute identifies the total size in
     number of impressions of the document(s) being submitted (see
     section 4.3.18 for the complete semantics).

     See note under "job-k-octets".

  "job-media-sheets" (integer(0:MAX))
     The client OPTIONALLY supplies this attribute.  The Printer object
     OPTIONALLY supports this attribute and the "job-media-sheets-
     supported" attribute (see section 4.4.32).  The client supplied
     "job-media-sheets" operation attribute identifies the total number
     of media sheets to be produced for this job (see section 4.3.19 for
     the complete semantics).

     See note under "job-k-octets".


Group 2: Job Template Attributes

     The client OPTIONALLY supplies a set of Job Template attributes as
     defined in section 4.2.  If the client is not supplying any Job
     Template attributes in the request, the client SHOULD omit Group 2
     rather than sending an empty group.  However, a Printer object MUST
     be able to accept an empty group.


Group 3: Document Content

     The client MUST supply the document data to be processed.


Note: In addition to the MANDATORY parameters required for every
operation request, the simplest Print-Job Request consists of just the
"attributes-charset" and "attributes-natural-language" operation
attributes; the "printer-uri" target operation attribute; the Document
Content and nothing else.  In this simple case, the Printer object:

  - creates a new Job object (the Job object contains a single
     document),


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  - stores a generated Job name in the "job-name" attribute in the
     natural language and charset requested (see Section 3.1.4.1) (if
     those are supported, otherwise using the Printer object's default
     natural language and charset), and
  - at job processing time, uses its corresponding default value
     attributes for the supported Job Template attributes that were not
     supplied by the client as IPP attribute or embedded instructions in
     the document data.



3.2.1.2 Print-Job Response

The Printer object MUST return to the client the following sets of
attributes as part of the Print-Job Response:

Group 1: Operation Attributes

  Status Message:
     In addition to the REQUIRED status code returned in every response,
     the response OPTIONALLY includes a "status-message" (text)
     operation attribute as described in sections 14 and 3.1.6.  If the
     client supplies unsupported or conflicting Job Template attributes
     or values, the Printer object MUST reject or accept the Print-Job
     request depending on the whether the client supplied a 'true' or
     'false' value for the "ipp-attribute-fidelity" operation attribute.
     See the Implementer's Guide [IPP-IIG] for a complete description of
     the suggested steps for processing a create request.

  Natural Language and Character Set:
     The "attributes-charset" and "attributes-natural-language"
     attributes as described in section 3.1.4.2.


Group 2: Unsupported Attributes

     This is a set of Operation and Job Template attributes supplied by
     the client (in the request) that are not supported by the Printer
     object or that conflict with one another (see the Implementer's
     Guide [IPP-IIG]).  If the Printer object is not returning any
     Unsupported Attributes in the response, the Printer object SHOULD
     omit Group 2 rather than sending an empty group.  However, a client
     MUST be able to accept an empty group.

     Unsupported attributes fall into three categories:

     1. The Printer object does not support the supplied attribute (no
          matter what the attribute syntax or value).
     2. The Printer object does support the attribute, but does not
          support some or all of the particular attribute syntaxes or
          values supplied by the client (i.e., the Printer object does
          not have those attribute syntaxes or values in its
          corresponding "xxx-supported" attribute).
     3. The Printer object does support the attributes and values
          supplied, but the particular values are in conflict with one


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          another, because they violate a constraint, such as not being
          able to staple transparencies.

     In the case of an unsupported attribute name, the Printer object
     returns the client-supplied attribute with a substituted "out-of-
     band" value of 'unsupported' indicating no support for the
     attribute itself (see the beginning of section 4.1).

     In the case of a supported attribute with one or more unsupported
     attribute syntaxes or values, the Printer object simply returns the
     client-supplied attribute with the unsupported attribute syntaxes
     or values as supplied by the client.  This indicates support for
     the attribute, but no support for that particular attribute syntax
     or value.  If the client supplies a multi-valued attribute with
     more than one value and the Printer object supports the attribute
     but only supports a subset of the client-supplied attribute
     syntaxes or values, the Printer object MUST return only those
     attribute syntaxes or values that are unsupported.

     In the case of two (or more) supported attribute values that are in
     conflict with one another (although each is supported
     independently, the values conflict when requested together within
     the same job), the Printer object MUST return all the values that
     it ignores or substitutes to resolve the conflict, but not any of
     the values that it is still using.  The choice for exactly how to
     resolve the conflict is implementation dependent.  See The
     Implementer's Guide [IPP-IIG] for an example.

     In these three cases, the value of the "ipp-attribute-fidelity"
     supplied by the client does not affect what the Printer object
     returns.  The value of "ipp-attribute-fidelity" only affects
     whether the Print-Job operation is accepted or rejected.  If the
     job is accepted, the client may query the job using the Get-Job-
     Attributes operation requesting the unsupported attributes that
     were returned in the create response to see which attributes were
     ignored (not stored on the Job object) and which attributes were
     stored with other (substituted) values.


Group 3: Job Object Attributes

  "job-uri" (uri):
     The Printer object MUST return the Job object's URI by returning
     the contents of the REQUIRED "job-uri" Job object attribute.  The
     client uses the Job object's URI when directing operations at the
     Job object.  The Printer object always uses its configured security
     policy when creating the new URI.  However, if the Printer object
     supports more than one URI, the Printer object also uses
     information about which URI was used in the Print-Job Request to
     generated the new URI so that the new URI references the correct
     access channel.  In other words, if the Print-Job Request comes in
     over a secure channel, the Printer object MUST generate a Job URI
     that uses the secure channel as well.



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  "job-id" (integer(1:MAX)):
     The Printer object MUST return the Job object's Job ID by returning
     the REQUIRED  "job-id" Job object attribute.  The client uses this
     "job-id" attribute in conjunction with the "printer-uri" attribute
     used in the Print-Job Request when directing Job operations at the
     Printer object.

  "job-state":
     The Printer object MUST return the Job object's REQUIRED "job-
     state" attribute. The value of this attribute (along with the value
     of the next attribute "job-state-reasons") is taken from a
     "snapshot" of the new Job object at some meaningful point in time
     (implementation defined) between when the Printer object receives
     the Print-Job Request and when the Printer object returns the
     response.

  "job-state-reasons":
     The Printer object OPTIONALLY returns the Job object's OPTIONAL
     "job-state-reasons" attribute.  If the Printer object supports this
     attribute then it MUST be returned in the response.  If this
     attribute is not returned in the response, the client can assume
     that the "job-state-reasons" attribute is not supported and will
     not be returned in a subsequent Job object query.

  "job-state-message":
     The Printer object OPTIONALLY returns the Job object's OPTIONAL
     "job-state-message" attribute.  If the Printer object supports this
     attribute then it MUST be returned in the response.  If this
     attribute is not returned in the response, the client can assume
     that the "job-state-message" attribute is not supported and will
     not be returned in a subsequent Job object query.

  "number-of-intervening-jobs":
     The Printer object OPTIONALLY returns the Job object's OPTIONAL
     "number-of-intervening-jobs" attribute.  If the Printer object
     supports this attribute then it MUST be returned in the response.
     If this attribute is not returned in the response, the client can
     assume that the "number-of-intervening-jobs" attribute is not
     supported and will not be returned in a subsequent Job object
     query.

     Note: Since any printer state information which affects a job's
     state is reflected in the "job-state" and "job-state-reasons"
     attributes, it is sufficient to return only these attributes and no
     specific printer status attributes.


Note: In addition to the MANDATORY parameters required for every
operation response, the simplest response consists of the just the
"attributes-charset" and "attributes-natural-language" operation
attributes and the "job-uri", "job-id", and "job-state" Job Object
Attributes.  In this simplest case, the status code is "successful-ok"
and there is no "status-message" operation attribute.



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3.2.2 Print-URI Operation

This OPTIONAL operation is identical to the Print-Job operation (section
3.2.1) except that a client supplies a URI reference to the document
data using the "document-uri" (uri) operation attribute (in Group 1)
rather than including the document data itself.  Before returning the
response, the Printer MUST validate that the Printer supports the
retrieval method (e.g., http, ftp, etc.) implied by the URI, and MUST
check for valid URI syntax.  If the client-supplied URI scheme is not
supported, i.e. the value is not in the Printer object's "referenced-
uri-scheme-supported" attribute, the Printer object MUST reject the
request and return the 'client-error-uri-scheme-not-supported' status
code.  See The Implementer's Guide [IPP-IIG] for suggested additional
checks.  The Printer NEED NOT follow the reference and validate the
contents of the reference.

If the Printer object supports this operation, it MUST support the
"reference-uri-schemes-supported" Printer attribute (see section
4.4.24).

It is up to the IPP object to interpret the URI and subsequently "pull"
the document from the source referenced by the URI string.


3.2.3 Validate-Job Operation

This REQUIRED operation is similar to the Print-Job operation (section
3.2.1) except that a client supplies no document data and the Printer
allocates no resources (i.e., it does not create a new Job object).
This operation is used only to verify capabilities of a printer object
against whatever attributes are supplied by the client in the Validate-
Job request.  By using the Validate-Job operation a client can validate
that an identical Print-Job operation (with the document data) would be
accepted. The Validate-Job operation also performs the same security
negotiation as the Print-Job operation (see section 8), so that a client
can check that the client and Printer object security requirements can
be met before performing a Print-Job operation.

Note: The Validate-Job operation does not accept a "document-uri"
attribute in order to allow a client to check that the same Print-URI
operation will be accepted, since the client doesn't send the data with
the Print-URI operation.  The client SHOULD just issue the Print-URI
request.

The Printer object returns the same status codes, Operation Attributes
(Group 1) and Unsupported Attributes (Group 2) as the Print-Job
operation.  However, no Job Object Attributes (Group 3) are returned,
since no Job object is created.


3.2.4 Create-Job Operation

This OPTIONAL operation is similar to the Print-Job operation (section
3.2.1) except that in the Create-Job request, a client does not supply
document data or any reference to document data.  Also, the client does

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not supply any of the "document-name", "document-format", "compression",
or "document-natural-language" operation attributes.  This operation is
followed by one or more Send-Document or Send-URI operations.  In each
of those operation requests, the client OPTIONALLY supplies the
"document-name", "document-format", and "document-natural-language"
attributes for each document in the multi-document Job object.

If a Printer object supports the Create-Job operation, it MUST also
support the Send-Document operation and also MAY support the Send-URI
operation.

If the Printer object supports this operation, it MUST support the
"multiple-operation-time-out" Printer attribute (see section 4.4.28).


3.2.5 Get-Printer-Attributes Operation

This REQUIRED operation allows a client to request the values of the
attributes of a Printer object.   In the request, the client supplies
the set of Printer attribute names and/or attribute group names in which
the requester is interested.  In the response, the Printer object
returns a corresponding attribute set with the appropriate attribute
values filled in.

For Printer objects, the possible names of attribute groups are:

  - 'job-template': all of the Job Template attributes that apply to a
     Printer object (the last two columns of the table in Section 4.2).
  - 'printer-description': the attributes specified in Section 4.4.
  - 'all': the special group 'all' that includes all supported
     attributes.


Since a client MAY request specific attributes or named groups, there is
a potential that there is some overlap.  For example, if a client
requests, 'printer-name' and 'all', the client is actually requesting
the "printer-name" attribute twice: once by naming it explicitly, and
once by inclusion in the 'all' group.  In such cases, the Printer object
NEED NOT return each attribute only once in the response even if it is
requested multiple times.  The client SHOULD NOT request the same
attribute in multiple ways.

It is NOT REQUIRED that a Printer object support all attributes
belonging to a group (since some attributes are OPTIONAL).  However, it
is REQUIRED that each Printer object support all group names.


3.2.5.1 Get-Printer-Attributes Request

The following sets of attributes are part of the Get-Printer-Attributes
Request:

Group 1: Operation Attributes




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  Natural Language and Character Set:
     The "attributes-charset" and "attributes-natural-language"
     attributes as described in section 3.1.4.1.

  Target:
     The "printer-uri" (uri) operation attribute which is the target for
     this operation as described in section 3.1.5.

  Requesting User Name:
     The "requesting-user-name" (name(MAX)) attribute SHOULD be supplied
     by the client as described in section 8.3.

  "requested-attributes" (1setOf keyword) :
     The client OPTIONALLY supplies a set of attribute names and/or
     attribute group names in whose values the requester is interested.
     The Printer object MUST support this attribute.  If the client
     omits this attribute, the Printer MUST respond as if this attribute
     had been supplied with a value of 'all'.

  "document-format" (mimeMediaType) :
     The client OPTIONALLY supplies this attribute.  The Printer object
     MUST support this attribute.  This attribute is useful for a
     Printer object to determine the set of supported attribute values
     that relate to the requested document format.  The Printer object
     MUST return the attributes and values that it uses to validate a
     job on a create or Validate-Job operation in which this document
     format is supplied. The Printer object SHOULD return only (1) those
     attributes that are supported for the specified format and (2) the
     attribute values that are supported for the specified document
     format.  By specifying the document format, the client can get the
     Printer object to eliminate the attributes and values that are not
     supported for a specific document format.  For example, a Printer
     object might have multiple interpreters to support both
     'application/postscript' (for PostScript) and 'text/plain' (for
     text) documents.  However, for only one of those interpreters might
     the Printer object be able to support "number-up" with values of
     '1', '2', and '4'.  For the other interpreter it might be able to
     only support "number-up" with a value of '1'. Thus a client can use
     the Get-Printer-Attributes operation to obtain the attributes and
     values that will be used to accept/reject a create job operation.

     If the Printer object does not distinguish between different sets
     of supported values for each different document format when
     validating jobs in the create and Validate-Job operations, it MUST
     NOT distinguish between different document formats in the Get-
     Printer-Attributes operation. If the Printer object does
     distinguish between different sets of supported values for each
     different document format specified by the client, this
     specialization applies only to the following Printer object
     attributes:

       - Printer attributes that are Job Template attributes ("xxx-
          default" "xxx-supported", and "xxx-ready" in the Table in
          Section 4.2),

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       - "pdl-override-supported",
       - "compression-supported",
       - "job-k-octets-supported",
       - "job-impressions-supported,
       - "job-media-sheets-supported"
       - "printer-driver-installer",
       - "color-supported", and
       - "reference-uri-schemes-supported"

     The values of all other Printer object attributes (including
     "document-format-supported") remain invariant with respect to the
     client supplied document format (except for new Printer description
     attribute as registered according to section 6.2).

     If the client omits this "document-format" operation attribute, the
     Printer object MUST respond as if the attribute had been supplied
     with the value of the Printer object's "document-format-default"
     attribute.  It is recommended that the client always supply a value
     for "document-format", since the Printer object's "document-format-
     default" may be 'application/octet-stream', in which case the
     returned attributes and values are for the union of the document
     formats that the Printer can automatically sense.  For more
     details, see the description of the 'mimeMediaType' attribute
     syntax in section 4.1.9.

     If the client supplies a value for the "document-format" Operation
     attribute that is not supported by the Printer, i.e., is not among
     the values of the Printer object's "document-format-supported"
     attribute, the Printer object MUST reject the operation and return
     the 'client-error-document-format-not-supported' status code.


3.2.5.2 Get-Printer-Attributes Response

The Printer object returns the following sets of attributes as part of
the Get-Printer-Attributes Response:

Group 1: Operation Attributes

  Status Message:
     In addition to the REQUIRED status code returned in every response,
     the response OPTIONALLY includes a "status-message" (text)
     operation attribute as described in section 3.1.6.

  Natural Language and Character Set:
     The "attributes-charset" and "attributes-natural-language"
     attributes as described in section 3.1.4.2.


Group 2: Unsupported Attributes

     This is a set of Operation attributes supplied by the client (in
     the request) that are not supported by the Printer object or that
     conflict with one another (see sections 3.2.1.2 and 16).  The
     response NEED NOT contain the "requested-attributes" operation


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     attribute with any supplied values (attribute keywords) that were
     requested by the client but are not supported by the IPP object.
     If the Printer object is not returning any Unsupported Attributes
     in the response, the Printer object SHOULD omit Group 2 rather than
     sending an empty group.  However, a client MUST be able to accept
     an empty group.


Group 3: Printer Object Attributes

     This is the set of requested attributes and their current values.
     The Printer object ignores (does not respond with) any requested
     attribute which is not supported.  The Printer object MAY respond
     with a subset of the supported attributes and values, depending on
     the security policy in force.  However, the Printer object MUST
     respond with the 'unknown' value for any supported attribute
     (including all REQUIRED attributes) for which the Printer object
     does not know the value.  Also the Printer object MUST respond with
     the 'no-value' for any supported attribute (including all REQUIRED
     attributes) for which the system administrator has not configured a
     value.  See the description of the "out-of-band" values in the
     beginning of Section 4.1.


3.2.6 Get-Jobs Operation

This REQUIRED operation allows a client to retrieve the list of Job
objects belonging to the target Printer object.  The client may also
supply a list of Job attribute names and/or attribute group names.  A
group of Job object attributes will be returned for each Job object that
is returned.

This operation is similar to the Get-Job-Attributes operation, except
that this Get-Jobs operation returns attributes from possibly more than
one object (see the description of Job attribute group names in section
3.3.4).


3.2.6.1 Get-Jobs Request

The client submits the Get-Jobs request to a Printer object.

The following groups of attributes are part of the Get-Jobs Request:

Group 1: Operation Attributes

  Natural Language and Character Set:
     The "attributes-charset" and "attributes-natural-language"
     attributes as described in section 3.1.4.1.

  Target:
     The "printer-uri" (uri) operation attribute which is the target for
     this operation as described in section 3.1.5.




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  Requesting User Name:
     The "requesting-user-name" (name(MAX)) attribute SHOULD be supplied
     by the client as described in section 8.3.

  "limit" (integer(1:MAX)):
     The client OPTIONALLY supplies this attribute.  The Printer object
     MUST support this attribute. It is an integer value that indicates
     a limit to the number of Job objects returned.  The limit is a
     "stateless limit" in that if the value supplied by the client is
     'N', then only the first 'N' jobs are returned in the Get-Jobs
     Response.  There is no mechanism to allow for the next 'M' jobs
     after the first 'N' jobs.  If the client does not supply this
     attribute, the Printer object responds with all applicable jobs.

  "requested-attributes" (1setOf keyword):
     The client OPTIONALLY supplies this attribute.  The Printer object
     MUST support this attribute.  It is a set of Job attribute names
     and/or attribute groups names in whose values the requester is
     interested.  This set of attributes is returned for each Job object
     that is returned.  The allowed attribute group names are the same
     as those defined in the Get-Job-Attributes operation in section
     3.3.4.  If the client does not supply this attribute, the Printer
     MUST respond as if the client had supplied this attribute with two
     values: 'job-uri' and 'job-id'.

  "which-jobs" (keyword):
     The client OPTIONALLY supplies this attribute.  The Printer object
     MUST support this attribute.  It indicates which Job objects MUST
     be returned by the Printer object. The values for this attribute
     are:

       'completed': This includes any Job object whose state is
          'completed', 'canceled', or 'aborted'.
       'not-completed': This includes any Job object whose state is
          'pending', 'processing', 'processing-stopped', or 'pending-
          held'.

     A Printer object MUST support both values.  However, if the
     implementation does not keep jobs in the 'completed', 'canceled',
     and 'aborted' states, then it returns no jobs when the 'completed'
     value is supplied.

     If a client supplies some other value, the Printer object MUST copy
     the attribute and the unsupported value to the Unsupported
     Attributes response group, reject the request, and return the
     'client-error-attributes-or-values-not-supported' status code.

     If the client does not supply this attribute, the Printer object
     MUST respond as if the client had supplied the attribute with a
     value of 'not-completed'.

  "my-jobs" (boolean):
     The client OPTIONALLY supplies this attribute.  The Printer object
     MUST support this attribute.  It indicates whether all jobs or just

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     the jobs submitted by the requesting user of this request  MUST be
     returned by the Printer object.  If the client does not supply this
     attribute, the Printer object MUST respond as if the client had
     supplied the attribute with a value of 'false', i.e., all jobs.
     The means for authenticating the requesting user and matching the
     jobs is described in section 8.

3.2.6.2 Get-Jobs Response

The Printer object returns all of the Job objects that match the
criteria as defined by the attribute values supplied by the client in
the request.  It is possible that no Job objects are returned since
there may literally be no Job objects at the Printer, or there may be no
Job objects that match the criteria supplied by the client.  If the
client requests any Job attributes at all, there is a set of Job Object
Attributes returned for each Job object.

Group 1: Operation Attributes

  Status Message:
     In addition to the REQUIRED status code returned in every response,
     the response OPTIONALLY includes a "status-message" (text)
     operation attribute as described in sections 14 and 3.1.6.

  Natural Language and Character Set:
     The "attributes-charset" and "attributes-natural-language"
     attributes as described in section 3.1.4.2.


Group 2: Unsupported Attributes

     This is a set of Operation attributes supplied by the client (in
     the request) that are not supported by the Printer object or that
     conflict with one another (see sections 3.2.1.2 and the
     Implementer's Guide [IPP-IIG]).  The response NEED NOT contain the
     "requested-attributes" operation attribute with any supplied values
     (attribute keywords) that were requested by the client but are not
     supported by the IPP object.  If the Printer object is not
     returning any Unsupported Attributes in the response, the Printer
     object SHOULD omit Group 2 rather than sending an empty group.
     However, a client MUST be able to accept an empty group.


Groups 3 to N: Job Object Attributes

     The Printer object responds with one set of Job Object Attributes
     for each returned Job object.  The Printer object ignores (does not
     respond with) any requested attribute or value which is not
     supported or which is restricted by the security policy in force,
     including whether the requesting user is the user that submitted
     the job (job originating user) or not (see section 8).  However,
     the Printer object MUST respond with the 'unknown' value for any
     supported attribute (including all REQUIRED attributes) for which
     the Printer object does not know the value, unless it would violate
     the security policy.  See the description of the "out-of-band"
     values in the beginning of Section 4.1.


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     Jobs are returned in the following order:

       - If the client requests all 'completed' Jobs (Jobs in the
          'completed', 'aborted', or 'canceled' states), then the Jobs
          are returned newest to oldest (with respect to actual
          completion time)
       - If the client requests all 'not-completed' Jobs (Jobs in the
          'pending', 'processing', 'pending-held', and 'processing-
          stopped' states), then Jobs are returned in relative
          chronological order of expected time to complete (based on
          whatever scheduling algorithm is configured for the Printer
          object).


3.2.7 Pause-Printer Operation

This OPTIONAL operation allows a client to stop the Printer object from
scheduling jobs on all its devices.  Depending on implementation, the
Pause-Printer operation MAY also stop the Printer from processing the
current job or jobs.  Any job that is currently being printed is either
stopped as soon as the implementation permits or is completed, depending
on implementation.  The Printer object MUST still accept create
operations to create new jobs, but MUST prevent any jobs from entering
the 'processing' state.

If the Pause-Printer operation is supported, then the Resume-Printer
operation MUST be supported, and vice-versa.

The IPP Printer stops the current job(s) on its device(s) that were in
the 'processing' or 'processing-stopped' states as soon as the
implementation permits.  If the implementation supports the "printer-
state-reasons" attribute and the devices will take appreciable time to
stop, the IPP Printer adds the 'moving-to-paused' value to the Printer
object's "printer-state-reasons" attribute (see section 4.4.11).  When
the device(s) have all stopped, the IPP Printer transitions the Printer
object to the 'stopped' state, removes the 'moving-to-paused' value, if
present, and adds the 'paused' value to the Printer object's "printer-
state-reasons" attribute.

When the current job(s) complete that were in the 'processing' state,
the IPP Printer transitions them to the 'completed' state.  When the
current job(s) stop in mid processing that were in the 'processing'
state, the IPP Printer transitions them to the 'processing-stopped'
state and, if the "job-state-reasons" attribute is supported, adds the
'printer-stopped' value to the job's "job-state-reasons" attribute.

Note:  for any jobs that are 'pending' or 'pending-held', the 'printer-
stopped' value of the jobs' "job-state-reasons" attribute also applies.
However, the IPP Printer NEED NOT update those jobs' "job-state-reasons"
attributes and only need return the 'printer-stopped' value when those
jobs are queried (so-called "lazy evaluation").



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Whether the Pause-Printer operation affects jobs that were submitted to
the device from other sources than the IPP Printer object in the same
way that the Pause-Printer operation affects jobs that were submitted to
the IPP Printer object using IPP, depends on implementation, i.e., on
whether the IPP protocol is being used as a universal management
protocol or just to manage IPP jobs, respectively.

The IPP Printer MUST accept the request in any state and transition the
Printer to the indicated new "printer-state" before returning as
follows:

Current    New        "printer  IPP Printer's response status
"printer-  "printer-  -state-   code and action:
state"     state"     reasons"

'idle'     'stopped'  'paused'  'successful-ok'

'processin 'processin 'moving-  OPTION 1: 'successful-ok';
g'         g'         to-       Later, when all output has
                        paused'   stopped, the "printer-state"
                                  becomes 'stopped', and the
                                  'paused' value replaces the
                                  'moving-to-paused' value in the
                                  "printer-state-reasons"
                                  attribute

'processin 'stopped'  'paused'  OPTION 2: 'successful-ok';
g'                               all device output stopped
                                  immediately

'stopped'  'stopped'  'paused'  'successful-ok'

Access Rights: The requesting user must be an operator or administrator
of the Printer object.  Otherwise, the IPP Printer MUST reject the
operation and return:  'client-error-forbidden', 'client-error-not-
authenticated', or 'client-error-not-authorized' as appropriate.


3.2.7.1 Pause-Printer Request

The following groups of attributes are part of the Pause-Printer
Request:

Group 1: Operation Attributes

  Natural Language and Character Set:
     The "attributes-charset" and "attributes-natural-language"
     attributes as described in section 3.1.4.1.

  Target:
     The "printer-uri" (uri) operation attribute which is the target for
     this operation as described in section 3.1.5.

  Requesting User Name:
     The "requesting-user-name" (name(MAX)) attribute SHOULD be supplied
     by the client as described in section 8.3.





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3.2.7.2 Pause-Printer Response

The following groups of attributes are part of the Pause-Printer
Response:

Group 1: Operation Attributes

  Status Message:
     In addition to the REQUIRED status code returned in every response,
     the response OPTIONALLY includes a "status-message" (text)
     operation attribute as described in section 3.1.6.

  Natural Language and Character Set:
     The "attributes-charset" and "attributes-natural-language"
     attributes as described in section 3.1.4.2.


Group 2: Unsupported Attributes

     This is a set of Operation attributes supplied by the client (in
     the request) that are not supported by the Printer object or that
     conflict with one another (see sections 3.2.1.2 and 16).

3.2.8 Resume-Printer Operation

This operation allows a client to resume the Printer object scheduling
jobs on all its devices.  If the Printer object supports the "printer-
state-reasons" attribute, it MUST remove the 'paused' and 'moving-to-
paused' values from the Printer object's "printer-state-reasons"
attribute, if present.  If there are no other reasons to keep a device
paused (such as media-jam), the IPP Printer transitions itself to the
'processing' or 'idle' states, depending on whether there are jobs to be
processed or not, respectively, and the device(s) resume processing
jobs.

If the Pause-Printer operation is supported, then the Resume-Printer
operation MUST be supported, and vice-versa.

The IPP Printer removes the 'printer-stopped' value from any job's "job-
state-reasons" attributes contained in that Printer.

The IPP Printer MUST accept the request in any state, transition the
Printer object to the indicated new state as follows:

Current      New "printer-  IPP Printer's response status code
"printer-    state"         and action:
state"

'idle'       'idle'         'successful-ok'

'processing  'processing'   'successful-ok'
'

'stopped'    'processing'   'successful-ok';
                            when there are jobs to be
                            processed

'stopped'    'idle'         'successful-ok';
                            when there are no jobs to be


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Current      New "printer-  IPP Printer's response status code
"printer-    state"         and action:
state"

                            processed.

Access Rights: The requesting user must be an operator or administrator
of the Printer object.  Otherwise, the IPP Printer MUST reject the
operation and return:  'client-error-forbidden', 'client-error-not-
authenticated', or 'client-error-not-authorized' as appropriate.

The Resume-Printer Request and Resume-Printer Response have the same
attribute groups and attributes as the Pause-Printer operation (see
sections 3.2.7.1 and 3.2.7.2).


3.2.9 Purge-Jobs Operation

This OPTIONAL operation allows a client to remove all jobs from an IPP
Printer object, regardless of their job states, including jobs in the
Printer object's Job History (see Section 4.3.7.1).  After a Purge-Jobs
operation has been performed, a Printer object MUST return no jobs in
subsequent Get-Job-Attributes and Get-Jobs responses (until new jobs are
submitted).

Whether the Purge-Jobs (and Get-Jobs) operation affects jobs that were
submitted to the device from other sources than the IPP Printer object
in the same way that the Purge-Jobs operation affects jobs that were
submitted to the IPP Printer object using IPP, depends on
implementation, i.e., on whether the IPP protocol is being used as a
universal management protocol or just to manage IPP jobs, respectively.

Note:  if an operator wants to cancel all jobs without clearing out the
Job History, the operator uses the Cancel-Job operation on each job
instead of using the Purge-Job operation.

The Printer object MUST accept this operation in any state and
transition the Printer object to the 'idle' state.

Access Rights: The requesting user must be an operator or administrator
of the Printer object.  Otherwise, the IPP object MUST reject the
operation and return: client-error-forbidden, client-error-not-
authenticated, and client-error-not-authorized as appropriate.

The Purge-Jobs Request and Purge-Jobs Response have the same attribute
groups and attributes as the Pause-Printer operation (see sections
3.2.7.1 and 3.2.7.2).


3.3 Job Operations


All Job operations are directed at Job objects.  A client MUST always
supply some means of identifying the Job object in order to identify the
correct target of the operation.  That job identification MAY either be
a single Job URI or a combination of a Printer URI with a Job ID.  The


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IPP object implementation MUST support both forms of identification for
every job.


3.3.1 Send-Document Operation

This OPTIONAL operation allows a client to create a multi-document Job
object that is initially "empty" (contains no documents).  In the
Create-Job response, the Printer object returns the Job object's URI
(the "job-uri" attribute) and the Job object's 32-bit identifier (the
"job-id" attribute).  For each new document that the client desires to
add, the client uses a Send-Document operation.  Each Send-Document
Request contains the entire stream of document data for one document.

Since the Create-Job and the send operations (Send-Document or Send-URI
operations) that follow could occur over an arbitrarily long period of
time for a particular job, a client MUST send another send operation
within an IPP Printer defined minimum time interval after the receipt of
the previous request for the job.  If a Printer object supports multiple
document jobs, the Printer object MUST support the "multiple-operation-
time-out" attribute (see section 4.4.28).  This attribute indicates the
minimum number of seconds the Printer object will wait for the next send
operation before taking some recovery action.

An IPP object MUST recover from an errant client that does not supply a
send operation, sometime after the minimum time interval specified by
the Printer object's "multiple-operation-time-out" attribute.  Such
recovery MAY include any of the following or other recovery actions:

  1. Assume that the Job is an invalid job, start the process of
     changing the job state to 'aborted', add the 'aborted-by-system'
     value to the job's "job-state-reasons" attribute (see section
     4.3.8), if supported, and clean up all resources associated with
     the Job.  In this case, if another send operation is finally
     received, the Printer responds with an "client-error-not-possible"
     or "client-error-not-found" depending on whether or not the Job
     object is still around when the send operation finally arrives.
  2. Assume that the last send operation received was in fact the last
     document (as if the "last-document" flag had been set to 'true'),
     close the Job object, and proceed to process it (i.e., move the
     Job's state to 'pending').
  3. Assume that the last send operation received was in fact the last
     document, close the Job, but move it to the 'pending-held' and add
     the 'submission-interrupted' value to the job's "job-state-reasons"
     attribute (see section 4.3.8), if supported.  This action allows
     the user or an operator to determine whether to continue processing
     the Job by moving it back to the 'pending' state using the Release-
     Job operation (see section 3.3.6) or to cancel the job using the
     Cancel-Job operation (see section 3.3.3).


Each implementation is free to decide the "best" action to take
depending on local policy, whether any documents have been added,
whether the implementation spools jobs or not,  and/or any other piece
of information available to it.  If the choice is to abort the Job


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object, it is possible that the Job object may already have been
processed to the point that some media sheet pages have been printed.


3.3.1.1 Send-Document Request

The following attribute sets are part of the Send-Document Request:

Group 1: Operation Attributes

  Natural Language and Character Set:
     The "attributes-charset" and "attributes-natural-language"
     attributes as described in section 3.1.4.1.

  Target:
     Either (1) the "printer-uri" (uri) plus "job-id" (integer(1:MAX))or
     (2) the "job-uri" (uri) operation attribute(s) which define the
     target for this operation as described in section 3.1.5.

  Requesting User Name:
     The "requesting-user-name" (name(MAX)) attribute SHOULD be supplied
     by the client as described in section 8.3.

  "document-name" (name(MAX)):
     The client OPTIONALLY supplies this attribute.  The Printer object
     MUST support this attribute.  It contains the client supplied
     document name.  The document name MAY be different than the Job
     name.  It might be helpful, but NEED NOT be unique across multiple
     documents in the same Job.  Typically, the client software
     automatically supplies the document name on behalf of the end user
     by using a file name or an application generated name.  See the
     description of the "document-name" operation attribute in the
     Print-Job Request (section 3.2.1.1) for more information about this
     attribute.

  "document-format" (mimeMediaType) :
     The client OPTIONALLY supplies this attribute.  The Printer object
     MUST support this attribute.  The value of this attribute
     identifies the format of the supplied document data.  If the client
     does not supply this attribute, the Printer object assumes that the
     document data is in the format defined by the Printer object's
     "document-format-default" attribute.  If the client supplies this
     attribute, but the value is not supported by the Printer object,
     i.e., the value is not one of the values of the Printer object's
     "document-format-supported" attribute, the Printer object MUST
     reject the request and return the 'client-error-document-format-
     not-supported' status code.

  "document-natural-language" (naturalLanguage):
     The client OPTIONALLY supplies this attribute.  The Printer object
     OPTIONALLY supports this attribute.  This attribute specifies the
     natural language of the document for those document-formats that
     require a specification of the natural language in order to image
     the document unambiguously.  There are no particular values
     required for the Printer object to support.

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  "compression" (type3 keyword)
     The client OPTIONALLY supplies this attribute.  The Printer object
     OPTIONALLY supports this attribute and the "compression-supported"
     attribute (see section 4.4.29).  The client supplied "compression"
     operation attribute identifies the compression algorithm used on
     the document data.  If the client omits this attribute, the Printer
     object MUST assume that the data is not compressed.  If the client
     supplies the attribute and the Printer object supports the
     attribute, the Printer object MUST use the corresponding
     decompression algorithm on the document data. If the client
     supplies this attribute, but the value is not supported by the
     Printer object, i.e., the value is not one of the values of the
     Printer object's "compression-supported" attribute, the Printer
     object MUST copy the attribute and its value to the Unsupported
     Attributes response group, reject the request, and return the
     'client-error-attributes-or-values-not-supported' status code.

  "last-document" (boolean):
     The client MUST supply this attribute.  The Printer object MUST
     support this attribute. It is a boolean flag that is set to 'true'
     if this is the last document for the Job, 'false' otherwise.


Group 2: Document Content

     The client MUST supply the document data if the "last-document"
     flag is set to 'false'.  However, since a client might not know
     that the previous document sent with a Send-Document (or Send-URI)
     operation was the last document (i.e., the "last-document"
     attribute was set to 'false'), it is legal to send a Send-Document
     request with no document data where the "last-document" flag is set
     to 'true'.  Such a request MUST NOT increment the value of the Job
     object's "number-of-documents" attribute, since no real document
     was added to the job.

3.3.1.2 Send-Document Response

The following sets of attributes are part of the Send-Document Response:

Group 1: Operation Attributes

  Status Message:
     In addition to the REQUIRED status code returned in every response,
     the response OPTIONALLY includes a "status-message" (text)
     operation attribute as described in sections 14 and 3.1.6.

  Natural Language and Character Set:
     The "attributes-charset" and "attributes-natural-language"
     attributes as described in section 3.1.4.2.


Group 2: Unsupported Attributes

     This is a set of Operation attributes supplied by the client (in
     the request) that are not supported by the Printer object or that


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     conflict with one another (see sections 3.2.1.2 and the
     Implementer's Guide [IPP-IIG]).  If the Printer object is not
     returning any Unsupported Attributes in the response, the Printer
     object SHOULD omit Group 2 rather than sending an empty group.
     However, a client MUST be able to accept an empty group.


Group 3: Job Object Attributes

     This is the same set of attributes as described in the Print-Job
     response (see section 3.2.1.2).


3.3.2 Send-URI Operation

This OPTIONAL operation is identical to the Send-Document operation (see
section 3.3.1) except that a client MUST supply a URI reference
("document-uri" operation attribute) rather than the document data
itself.  If a Printer object supports this operation, clients can use
both Send-URI or Send-Document operations to add new documents to an
existing multi-document Job object.  However, if a client needs to
indicate that the previous Send-URI or Send-Document was the last
document,  the client MUST use the Send-Document operation with no
document data and the "last-document" flag set to 'true' (rather than
using a Send-URI operation with no "document-uri" operation attribute).

If a Printer object supports this operation, it MUST also support the
Print-URI operation (see section 3.2.2).

The Printer object MUST validate the syntax and URI scheme of the
supplied URI before returning a response, just as in the Print-URI
operation.


3.3.3 Cancel-Job Operation

This REQUIRED operation allows a client to cancel a Print Job from the
time the job is created up to the time it is completed, canceled, or
aborted.  Since a Job might already be printing by the time a Cancel-Job
is received, some media sheet pages might be printed before the job is
actually terminated.


3.3.3.1 Cancel-Job Request

The following groups of attributes are part of the Cancel-Job Request:

Group 1: Operation Attributes

  Natural Language and Character Set:
     The "attributes-charset" and "attributes-natural-language"
     attributes as described in section 3.1.4.1.

  Target:
     Either (1) the "printer-uri" (uri) plus "job-id"
     (integer(1:MAX))or (2) the "job-uri" (uri) operation attribute(s)


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     which define the target for this operation as described in section
     3.1.5.

  Requesting User Name:
     The "requesting-user-name" (name(MAX)) attribute SHOULD be supplied
     by the client as described in section 8.3.

  "message" (text(127)):
     The client OPTIONALLY supplies this attribute.  The Printer object
     OPTIONALLY supports this attribute. It is a message to the
     operator.  This "message" attribute is not the same as the "job-
     message-from-operator" attribute.  That attribute is used to report
     a message from the operator to the end user that queries that
     attribute.  This "message" operation attribute is used to send a
     message from the client to the operator along with the operation
     request.  It is an implementation decision of how or where to
     display this message to the operator (if at all).


3.3.3.2 Cancel-Job Response

The following sets of attributes are part of the Cancel-Job Response:

Group 1: Operation Attributes

  Status Message:
     In addition to the REQUIRED status code returned in every response,
     the response OPTIONALLY includes a "status-message" (text)
     operation attribute as described in sections 14 and 3.1.6.

     If the job is already in the 'completed', 'aborted', or 'canceled'
     state, or the 'process-to-stop-point' value is set in the Job's
     "job-state-reasons" attribute, the Printer object MUST reject the
     request and return the 'client-error-not-possible' error status
     code.

  Natural Language and Character Set:
     The "attributes-charset" and "attributes-natural-language"
     attributes as described in section 3.1.4.2.


Group 2: Unsupported Attributes

     This is a set of Operation attributes supplied by the client (in
     the request) that are not supported by the Printer object or that
     conflict with one another (see section 3.2.1.2 and the
     Implementer's Guide [IPP-IIG]).  If the Printer object is not
     returning any Unsupported Attributes in the response, the Printer
     object SHOULD omit Group 2 rather than sending an empty group.
     However, a client MUST be able to accept an empty group.



Once a successful response has been sent, the implementation guarantees
that the Job will eventually end up in the 'canceled' state. Between the
time of the Cancel-Job operation is accepted and when the job enters the

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'canceled' job-state (see section 4.3.7), the "job-state-reasons"
attribute SHOULD contain the ' processing-to-stop-point ' value which
indicates to later queries that although the Job might still be
'processing', it will eventually end up in the 'canceled' state, not the
'completed' state.


3.3.4 Get-Job-Attributes Operation

This REQUIRED operation allows a client to request the values of
attributes of a Job object and it is almost identical to the Get-
Printer-Attributes operation (see section 3.2.5).  The only differences
are that the operation is directed at a Job object rather than a Printer
object, there is no "document-format" operation attribute used when
querying a Job object, and the returned attribute group is a set of Job
object attributes rather than a set of Printer object attributes.

For Jobs, the possible names of attribute groups are:

  - 'job-template': all of the Job Template attributes that apply to a
     Job object (the first column of the table in Section 4.2).
  - 'job-description': all of the Job Description attributes specified
     in Section 4.3.
  - 'all': the special group 'all' that includes all supported
     attributes.


Since a client MAY request specific attributes or named groups, there is
a potential that there is some overlap.  For example, if a client
requests, 'job-name' and 'job-description', the client is actually
requesting the "job-name" attribute once by naming it explicitly, and
once by inclusion in the 'job-description' group.  In such cases, the
Printer object NEED NOT return the attribute only once in the response
even if it is requested multiple times.  The client SHOULD NOT request
the same attribute in multiple ways.

It is NOT REQUIRED that a Job object support all attributes belonging to
a group (since some attributes are OPTIONAL).  However it is REQUIRED
that each Job object support all group names.


3.3.4.1 Get-Job-Attributes Request

The following groups of attributes are part of the Get-Job-Attributes
Request when the request is directed at a Job object:

Group 1: Operation Attributes

  Natural Language and Character Set:
     The "attributes-charset" and "attributes-natural-language"
     attributes as described in section 3.1.4.1.

  Target:
     Either (1) the "printer-uri" (uri) plus "job-id" (integer(1:MAX))
     or (2) the "job-uri" (uri) operation attribute(s) which define the
     target for this operation as described in section 3.1.5.


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  Requesting User Name:
     The "requesting-user-name" (name(MAX)) attribute SHOULD be supplied
     by the client as described in section 8.3.

  "requested-attributes" (1setOf keyword) :
     The client OPTIONALLY supplies this attribute.  The IPP object MUST
     support this attribute.   It is a set of attribute names and/or
     attribute group names in whose values the requester is interested.
     If the client omits this attribute, the IPP object MUST respond as
     if this attribute had been supplied with a value of 'all'.


3.3.4.2 Get-Job-Attributes Response

The Printer object returns the following sets of attributes as part of
the Get-Job-Attributes Response:

Group 1: Operation Attributes

  Status Message:
     In addition to the REQUIRED status code returned in every response,
     the response OPTIONALLY includes a "status-message" (text)
     operation attribute as described in sections 14 and 3.1.6.

  Natural Language and Character Set:
     The "attributes-charset" and "attributes-natural-language"
     attributes as described in section 3.1.4.2.  The "attributes-
     natural-language" MAY be the natural language of the Job object,
     rather than the one requested.



Group 2: Unsupported Attributes

     This is a set of Operation attributes supplied by the client (in
     the request) that are not supported by the Printer object or that
     conflict with one another (see sections 3.2.1.2 and the
     Implementer's Guide [IPP-IIG]).  The response NEED NOT contain the
     "requested-attributes" operation attribute with any supplied values
     (attribute keywords) that were requested by the client but are not
     supported by the IPP object.  If the Printer object is not
     returning any Unsupported Attributes in the response, the Printer
     object SHOULD omit Group 2 rather than sending an empty group.
     However, a client MUST be able to accept an empty group.


Group 3: Job Object Attributes

     This is the set of requested attributes and their current values.
     The IPP object ignores (does not respond with) any requested
     attribute or value which is not supported or which is restricted by
     the security policy in force, including whether the requesting user
     is the user that submitted the job (job originating user) or not
     (see section 8).  However, the IPP object MUST respond with the
     'unknown' value for any supported attribute (including all REQUIRED


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     attributes) for which the IPP object does not know the value,
     unless it would violate the security policy.  See the description
     of the "out-of-band" values in the beginning of Section 4.1.

3.3.5 Hold-Job Operation

This OPTIONAL operation allows a client to hold a pending job in the
queue so that it is not eligible for scheduling.  If the Hold-Job
operation is supported, then the Release-Job operation MUST be
supported, and vice-versa.  The OPTIONAL "job-hold-until" operation
attribute allows a client to specify whether to hold the job
indefinitely or until a specified time period, if supported.

The IPP object MUST accept or reject the request based on the job's
current state and transition the job to the indicated new state as
follows:

Current "job-  New "job-      IPP object's response status
state"         state"         code and action:

'pending'      'pending-      'successful-ok'  See Note 1
               held'

'pending'      'pending'      'successful-ok'  See Note 2

'pending-      'pending-      'successful-ok'  See Note 1
held'          held'

'pending-      'pending'      'successful-ok'  See Note 2
held'

'processing'   'processing'   'client-error-not-possible'

'processing-   'processing-   'client-error-not-possible'
stopped'       stopped'

'completed'    'completed'    'client-error-not-possible'

'canceled'     'canceled'     'client-error-not-possible'

'aborted'      'aborted'      'client-error-not-possible'

Note 1:  If the OPTIONAL "job-state-reasons" attribute is supported and
if the implementation supports multiple reasons for a job to be in the
'pending-held' state, the IPP object MUST add the 'job-hold-until-
specified' value to the job's "job-state-reasons" attribute.

Note 2:  If the IPP object supports the "job-hold-until" operation
attribute, but the specified time period has already started (or is the
'no-hold' value) and there are no other reasons to hold the job, the IPP
object MUST make the job be a candidate for processing immediately (see
Section 4.2.2) by putting the job in the 'pending' state.

Note:  In order to keep the Hold-Job operation simple, such a request is
rejected when the job is in the 'processing' or 'processing-stopped'
states.  If an operation is needed to hold jobs while in these states,
it will be added as an additional operation, rather than overloading the
Hold-Job operation.  Then it is clear to clients by querying the Printer
object's "operations-supported" (see Section 4.4.13) and the Job
object's "job-state" (see Section 4.3.7) attributes which operations are
possible.


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Access Rights: The requesting user must either be the submitter of the
job or an operator or administrator of the Printer object (see Section
1).  Otherwise, the IPP object MUST reject the operation and return:
'client-error-forbidden', 'client-error-not-authenticated', or 'client-
error-not-authorized' as appropriate.


3.3.5.1 Hold-Job Request

The groups and operation attributes are the same as for a Cancel-Job
request (see section 3.3.3.1), with the addition of the following Group
1 Operation attribute:

  "job-hold-until" (type3 keyword | name(MAX)):
     The client OPTIONALLY supplies this Operation attribute.  The IPP
     object MUST support this operation attribute in a Hold-Job request,
     if it supports the "job-hold-until" Job template attribute in
     create operations.  See section 4.2.2.  The IPP object SHOULD
     support the "job-hold-until" Job Template attribute for use in job
     create operations with at least the 'indefinite' value, if it
     supports the Hold-Job operation.  Otherwise, a client cannot create
     a job and hold it immediately (without picking some supported time
     period in the future).

     If supplied and supported as specified in the Printer's "job-hold-
     until-supported" attribute, the IPP object copies the supplied
     operation attribute to the Job object, replacing the job's previous
     "job-hold-until" attribute, if present, and makes the job a
     candidate for scheduling during the supplied named time period.

     If supplied, but either the "job-hold-until" Operation attribute
     itself or the value supplied is not supported, the IPP object
     accepts the request, returns the unsupported attribute or value in
     the Unsupported Attributes Group according to section 3.2.1.2,
     returns the 'successful-ok-ignored-or-substituted-attributes, and
     holds the job indefinitely until a client performs a subsequent
     Release-Job operation.

     If the client (1) supplies a value that specifies a time period
     that has already started or the 'no-hold' value (meaning don't hold
     the job) and (2) the IPP object supports the "job-hold-until"
     operation attribute and there are no other reasons to hold the job,
     the IPP object MUST accept the operation and make the job be a
     candidate for processing immediately (see Section 4.2.2).

     If the client does not supply a "job-hold-until" Operation
     attribute in the request, the IPP object MUST populate the job
     object with a "job-hold-until" attribute with the 'indefinite'
     value (if IPP object supports the "job-hold-until" attribute) and
     hold the job indefinitely, until a client performs a Release-Job
     operation.






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3.3.5.2 Hold-Job Response

The groups and attributes are the same as for a Cancel-Job response (see
section 3.3.3.2).


3.3.6 Release-Job Operation

This OPTIONAL operation allows a client to release a previously held job
so that it is again eligible for scheduling.  If the Hold-Job operation
is supported, then the Release-Job operation MUST be supported, and
vice-versa.

This operation removes the "job-hold-until" job attribute, if present,
from the job object that had been supplied in the create or most recent
Hold-Job or Restart-Job operation and remove its effect on the job.   If
the OPTIONAL "job-state-reasons" attribute is supported, the IPP object
MUST remove the 'job-hold-until-specified' value from the job's "job-
state-reasons" attribute, if present.  See section 4.3.8.

The IPP object MUST accept or reject the request based on the job's
current state and transition the job to the indicated new state as
follows:

Current "job-  New "job-      IPP object's response status
state"         state"         code and action:

'pending'      'pending'      'successful-ok'  No effect on
                              the job.

'pending-      'pending-      'successful-ok'  See Note 1
held'          held'

'pending-      'pending'      'successful-ok'
held'

'processing'   'processing'   'successful-ok'  No effect on
                              the job.

'processing-   'processing-   'successful-ok'  No effect on
stopped'       stopped'       the job.

'completed'    'completed'    'client-error-not-possible'

'canceled'     'canceled'     'client-error-not-possible'

'aborted'      'aborted'      'client-error-not-possible'

Note 1:  If there are other reasons to keep the job in the 'pending-
held' state, such as 'resources-are-not-ready', the job remains in the
'pending-held' state.  Thus the 'pending-held' state is not just for
jobs that have the 'job-hold-until' applied to them, but are for any
reason to keep the job from being a candidate for scheduling and
processing, such as 'resources-are-not-ready'.  See the "job-hold-until"
attribute (section 4.2.2).

Access Rights: The requesting user must either be the submitter of the
job or an operator or administrator of the Printer object.  Otherwise,
the IPP object MUST reject the operation and return: 'client-error-
forbidden', 'client-error-not-authenticated', or 'client-error-not-
authorized' as appropriate.


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The Release-Job Request and Release-Job Response have the same attribute
groups and attributes as the Cancel-Job operation (see section 3.3.3.1
and 3.3.3.2).


3.3.7 Restart-Job Operation

This OPTIONAL operation allows a client to restart a job that is
retained in the queue after processing has completed (see section
4.3.7.1).

The job is moved to the 'pending' job state and restarts at the
beginning on the same IPP Printer object with the same attribute values.
The Job Description attributes that accumulate job progress, such as
"job-impressions-completed", "job-media-sheets-completed", and "job-k-
octets-processed", MUST be reset to 0 so that they give an accurate
record of the job from its restart point.  The job object MUST continue
to use the same "job-uri" and "job-id" attribute values.

Note:  If in the future an operation is needed that does not reset the
job progress attributes, then a new operation will be defined which
makes a copy of the job, assigns a new "job-uri" and "job-id" to the
copy and resets the job progress attributes in the new copy only.

The IPP object MUST accept or reject the request based on the job's
current state, transition the job to the indicated new state as follows:

Current "job-  New "job-      IPP object's response status
state"         state"         code and action:

'pending'      'pending'      'client-error-not-possible'.

'pending-      'pending-      'client-error-not-possible'.
held'          held'


'processing'   'processing'   'client-error-not-possible'.


'processing-
stopped'

'completed'    'pending'      'successful-ok' - job is started
                              over.

'completed'    'completed'    'client-error-not-possible' -
                              see Note 1

'canceled'     'pending'      'successful-ok' - job is started
                              over.

'canceled'     'canceled'     'client-error-not-possible' -
                              see Note 1

'aborted'      'pending'      'successful-ok' - job is started
                              over.

'aborted'      'aborted'      'client-error-not-possible' -
                              see Note 1





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Note 1:  If the Job Retention Period has expired for the job in this
state, then the IPP object rejects the operation.  See section 4.3.7.1.

Note:  In order to prevent a user from inadvertently restarting a job in
the middle, the Restart-Job request is rejected when the job is in the
'processing' or 'processing-stopped' states.  If in the future an
operation is needed to hold or restart jobs while in these states, it
will be added as an additional operation, rather than overloading the
Restart-Job operation, so that it is clear that the user intended that
the current job not be completed.

Access Rights: The requesting user must either be the submitter of the
job or an operator or administrator of the Printer object.  Otherwise,
the IPP object MUST reject the operation and return: 'client-error-
forbidden', 'client-error-not-authenticated', or 'client-error-not-
authorized' as appropriate.


3.3.7.1 Restart-Job Request

The groups and attributes are the same as for a Cancel-Job request (see
section 3.3.3.1), with the addition of the following Group 1 Operation
attribute:

  "job-hold-until" (type3 keyword | name(MAX)):
     The client OPTIONALLY supplies this attribute.  The IPP object MUST
     support this Operation attribute in a Restart-Job request, if it
     supports the "job-hold-until" Job Template attribute in create
     operations.  See section 4.2.2.  Otherwise, the IPP object NEED NOT
     support the "job-hold-until" Operation attribute in a Restart-Job
     request.

     If supplied and supported as specified in the Printer's "job-hold-
     until-supported" attribute, the IPP object copies the supplied
     Operation attribute to the Job object, replacing the job's previous
     "job-hold-until" attribute, if present, and makes the job a
     candidate for scheduling during the supplied named time period.
     See section 4.2.2.

     If supplied, but the value is not supported, the IPP object accepts
     the request, returns the unsupported attribute or value in the
     Unsupported Attributes Group according to section 3.2.1.2, returns
     the 'successful-ok-ignored-or-substituted-attributes' status code,
     and holds the job indefinitely until a client performs a subsequent
     Release-Job operation.

     If supplied, but the "job-hold-until" Operation attribute itself is
     not supported, the IPP object accepts the request, returns the
     unsupported attribute with the out-of-band 'unsupported' value in
     the Unsupported Attributes Group according to section 3.2.1.2,
     returns the 'successful-ok-ignored-or-substituted-attributes'
     status code, and restarts the job, i.e., ignores the "job-hold-
     until" attribute.




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     If the client (1) supplies a value that specifies a time period
     that has already started or the 'no-hold' value (meaning don't hold
     the job) and (2) the IPP object supports the "job-hold-until"
     operation attribute and there are no other reasons to hold the job,
     the IPP object makes the job a candidate for processing immediately
     (see Section 4.2.2).

     If the client does not supply a "job-hold-until" operation
     attribute in the request, the IPP object removes the "job-hold-
     until" attribute, if present, from the job.  If there are no other
     reasons to hold the job, the Restart-Job operation makes the job a
     candidate for processing immediately (see Section 4.2.2).


3.3.7.2 Restart-Job Response

The groups and attributes are the same as for a Cancel-Job response (see
section 3.3.3.2).

Note:  In the future an OPTIONAL Modify-Job operation may be specified
that allows the client to modify other attributes before releasing the
restarted job.



4. Object Attributes


This section describes the attributes with their corresponding attribute
syntaxes and values that are part of the IPP model.  The sections below
show the objects and their associated attributes which are included
within the scope of this protocol.  Many of these attributes are derived
from other relevant specifications:

  - Document Printing Application (DPA) [ISO10175]
  - RFC 1759 Printer MIB [RFC1759]


Each attribute is uniquely identified in this document using a "keyword"
(see section 13.2.1) which is the name of the attribute.  The keyword is
included in the section header describing that attribute.

Note:  Not only are keywords used to identify attributes, but one of the
attribute syntaxes described below is "keyword" so that some attributes
have keyword values.  Therefore, these attributes are defined as having
an attribute syntax that is a set of keywords.


4.1 Attribute Syntaxes


This section defines the basic attribute syntax types that all clients
and IPP objects MUST be able to accept in responses and accept in
requests, respectively.  Each attribute description in sections 3 and
3.3.5 includes the name of attribute syntax(es) in the heading (in
parentheses).  A conforming implementation of an attribute MUST include



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the semantics of the attribute syntax(es) so identified.  Section 6.3
describes how the protocol can be extended with new attribute syntaxes.

The attribute syntaxes are specified in the following sub-sections,
where the sub-section heading is the keyword name of the attribute
syntax inside the single quotes.  In operation requests and responses
each attribute value MUST be represented as one of the attribute
syntaxes specified in the sub-section heading for the attribute.  In
addition, the value of an attribute in a response (but not in a request)
MAY be one of the "out-of-band" values.   Standard "out-of-band" values
are:

  'unknown': The attribute is supported by the IPP object, but the
     value is unknown to the IPP object for some reason.
  'unsupported': The attribute is unsupported by the IPP object.  This
     value MUST be returned only as the value of an attribute in the
     Unsupported Attributes Group.
  'no-value': The attribute is supported by the Printer object, but the
     administrator has not yet configured a value.



The "Encoding and Transport" specification [IPP-PRO] defines mechanisms
for passing "out-of-band" values.  All attributes in a request MUST have
one or more values as defined in Sections 4.2 to 4.4.  Thus clients MUST
NOT supply attributes with "out-of-band" values.  All attributes in a
response MUST have one or more values as defined in Sections 4.2 to 4.4
or a single "out-of-band" value.

Most attributes are defined to have a single attribute syntax.  However,
a few attributes (e.g., "job-sheet", "media", "job-hold-until") are
defined to have several attribute syntaxes, depending on the value.
These multiple attribute syntaxes are separated by the "|" character in
the sub-section heading to indicate the choice.  Since each value MUST
be tagged as to its attribute syntax in the protocol, a single-valued
attribute instance may have any one of its attribute syntaxes and a
multi-valued attribute instance may have a mixture of its defined
attribute syntaxes.


4.1.1 'text'

A text attribute is an attribute whose value is a sequence of zero or
more characters encoded in a maximum of 1023 ('MAX') octets.  MAX is the
maximum length for each value of any text attribute.  However, if an
attribute will always contain values whose maximum length is much less
than MAX, the definition of that attribute will include a qualifier that
defines the maximum length for values of that attribute.  For example:
the "printer-location" attribute is specified as "printer-location
(text(127))".  In this case, text values for "printer-location" MUST NOT
exceed 127 octets; if supplied with a longer text string via some
external interface (other than the protocol), implementations are free
to truncate to this shorter length limitation.




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In this specification, all text attributes are defined using the 'text'
syntax.  However, 'text' is used only for brevity; the formal
interpretation of 'text' is: 'textWithoutLanguage | textWithLanguage'.
That is, for any attribute defined in this specification using the
'text' attribute syntax, all IPP objects and clients MUST support both
the 'textWithoutLanguage' and 'textWithLanguage' attribute syntaxes.
However, in actual usage and protocol execution, objects and clients
accept and return only one of the two syntax per attribute.  The syntax
'text' never appears "on-the-wire".

Both 'textWithoutLanguage' and 'textWithLanguage' are needed to support
the real world needs of interoperability between sites and systems that
use different natural languages as the basis for human communication.
Generally, one natural language applies to all text attributes in a
given request or response. The language is indicated by the "attributes-
natural-language" operation attribute defined in section 3.1.4 or
"attributes-natural-language" job attribute defined in section 4.3.24,
and there is no need to identify the natural language for each text
string on a value-by-value basis.  In these cases, the attribute syntax
'textWithoutLanguage' is used for text attributes.  In other cases, the
client needs to supply or the Printer object needs to return a text
value in a natural language that is different from the rest of the text
values in the request or response.  In these cases, the client or
Printer object uses the attribute syntax 'textWithLanguage' for text
attributes (this is the Natural Language Override mechanism described in
section 3.1.4).

The 'textWithoutLanguage' and 'textWithLanguage' attribute syntaxes are
described in more detail in the following sections.


4.1.1.1 'textWithoutLanguage'

The 'textWithoutLanguage' syntax indicates a value that is sequence of
zero or more characters.   Text strings are encoded using the rules of
some charset.  The Printer object MUST support the UTF-8 charset
[RFC2279] and MAY support additional charsets to represent 'text'
values, provided that the charsets are registered with IANA [IANA-CS].
See Section 4.1.7 for the specification of the 'charset' attribute
syntax, including restricted semantics and examples of charsets.


4.1.1.2 'textWithLanguage'

The 'textWithLanguage' attribute syntax is a compound attribute syntax
consisting of two parts: a 'textWithoutLanguage' part plus an additional
'naturalLanguage' (see section 4.1.8) part that overrides the natural
language in force.  The 'naturalLanguage' part explicitly identifies the
natural language that applies to the text part of that value and that
value alone.  For any give text attribute, the 'textWithoutLanguage'
part is limited to the maximum length defined for that attribute, but
the 'naturalLanguage' part is always limited to 63 octets. Using the
'textWithLanguage' attribute syntax rather than the normal
'textWithoutLanguage' syntax is the so-called Natural Language Override
mechanism and MUST be supported by all IPP objects and clients.

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If the attribute is multi-valued (1setOf text), then the
'textWithLanguage' attribute syntax MUST be used to explicitly specify
each attribute value whose natural language needs to be overridden.
Other values in a multi-valued 'text' attribute in a request or a
response revert to the natural language of the operation attribute.

In a create request, the Printer object MUST accept and store with the
Job object any natural language in the "attributes-natural-language"
operation attribute, whether the Printer object supports that natural
language or not.  Furthermore, the Printer object MUST accept and store
any 'textWithLanguage' attribute value, whether the Printer object
supports that natural language or not.  These requirements are
independent of the value of the "ipp-attribute-fidelity" operation
attribute that the client MAY supply.

Example:  If the client supplies the "attributes-natural-language"
operation attribute with the value:  'en' indicating English, but the
value of the "job-name" attribute is in French, the client MUST use the
'textWithLanguage' attribute syntax with the following two values:

  'fr': Natural Language Override indicating French
  'Rapport Mensuel': the job name in French


See the "Encoding and Transport" document [IPP-PRO] for a detailed
example of the 'textWithLanguage' attribute syntax.


4.1.2 'name'

This syntax type is used for user-friendly strings, such as a Printer
name, that, for humans, are more meaningful than identifiers.  Names are
never translated from one natural language to another.  The 'name'
attribute syntax is essentially the same as 'text', including the
REQUIRED support of UTF-8 except that the sequence of characters is
limited so that its encoded form MUST NOT exceed 255 (MAX) octets.

Also like 'text', 'name' is really an abbreviated notation for either
'nameWithoutLanguage' or 'nameWithLanguage'.  That is,  all IPP objects
and clients MUST support both the 'nameWithoutLanguage' and
'nameWithLanguage' attribute syntaxes.  However, in actual usage and
protocol execution, objects and clients accept and return only one of
the two syntax per attribute.  The syntax 'name' never appears "on-the-
wire".

Note:  Only the 'text' and 'name' attribute syntaxes permit the Natural
Language Override mechanism.

Some attributes are defined as 'type3 keyword | name'.  These attributes
support values that are either type3 keywords or names.  This dual-
syntax mechanism enables a site administrator to extend these attributes
to legally include values that are locally defined by the site
administrator.  Such names are not registered with IANA.




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4.1.2.1 'nameWithoutLanguage'

The nameWithoutLanguage' syntax indicates a value that is sequence of
zero or more characters so that its encoded form does not exceed MAX
octets.


4.1.2.2 'nameWithLanguage'

The 'nameWithLanguage' attribute syntax is a compound attribute syntax
consisting of two parts: a 'nameWithoutLanguage' part plus an additional
'naturalLanguage' (see section 4.1.8) part that overrides the natural
language in force.  The 'naturalLanguage' part explicitly identifies the
natural language that applies to that name value and that name value
alone.

The 'nameWithLanguage' attribute syntax behaves the same as  the
'textWithLanguage' syntax.  If a name is in a language that is different
than the rest of the object or operation, then this 'nameWithLanguage'
syntax is used rather than the generic 'nameWithoutLanguage' syntax.

Example:  If the client supplies the "attributes-natural-language"
operation attribute with the value:  'en' indicating English, but the
"printer-name" attribute is in German, the client MUST use the
'nameWithLanguage' attribute syntax as follows:

  'de':  Natural Language Override indicating German
  'Farbdrucker':  the Printer name in German


4.1.2.3 Matching 'name' attribute values

For purposes of matching two 'name' attribute values for equality, such
as in job validation (where a client-supplied value for attribute "xxx"
is checked to see if the value is among the values of the Printer
object's corresponding "xxx-supported" attribute), the following match
rules apply:

     1. 'keyword' values never match 'name' values.

     2. 'name' (nameWithoutLanguage and nameWithLanguage) values match
     if (1) the name parts match and (2) the Associated Natural-Language
     parts (see section 3.1.4.1) match.  The matching rules are:

          a. the name parts match if the two names are identical
          character by character, except it is RECOMMENDED that case be
          ignored.  For example: 'Ajax-letter-head-white' MUST match
          'Ajax-letter-head-white' and SHOULD match 'ajax-letter-head-
          white' and 'AJAX-LETTER-HEAD-WHITE'.

          b. the Associated Natural-Language parts match if the shorter
          of the two meets the syntactic requirements of RFC 1766
          [RFC1766] and matches byte for byte with the longer.  For
          example, 'en' matches 'en', 'en-us' and 'en-gb', but matches
          neither 'fr' nor 'e'.

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4.1.3 'keyword'

The 'keyword' attribute syntax is a sequence of characters, length: 1 to
255, containing only the US-ASCII [ASCII] encoded values for lowercase
letters ("a" - "z"), digits ("0" - "9"), hyphen ("-"), dot ("."), and
underscore ("_").  The first character MUST be a lowercase letter.
Furthermore, keywords MUST be in U.S. English.

This syntax type is used for enumerating semantic identifiers of
entities in the abstract protocol, i.e., entities identified in this
document.  Keywords are used as attribute names or values of attributes.
Unlike 'text' and 'name' attribute values, 'keyword' values MUST NOT use
the Natural Language Override mechanism, since they MUST always be US-
ASCII and U.S. English.

Keywords are for use in the protocol.  A user interface will likely
provide a mapping between protocol keywords and displayable user-
friendly words and phrases which are localized to the natural language
of the user.  While the keywords specified in this document MAY be
displayed to users whose natural language is U.S. English, they MAY be
mapped to other U.S. English words for U.S. English users, since the
user interface is outside the scope of this document.

In the definition for each attribute of this syntax type, the full set
of defined keyword values for that attribute are listed.

When a keyword is used to represent an attribute (its name), it MUST be
unique within the full scope of all IPP objects and attributes.  When a
keyword is used to represent a value of an attribute, it MUST be unique
just within the scope of that attribute.  That is, the same keyword MUST
NOT be used for two different values within the same attribute to mean
two different semantic ideas.  However, the same keyword MAY be used
across two or more attributes, representing different semantic ideas for
each attribute.  Section 6.1 describes how the protocol can be extended
with new keyword values.  Examples of attribute name keywords:

  "job-name"
  "attributes-charset"


Note:  This document uses "type1", "type2", and "type3" prefixes to the
"keyword" basic syntax to indicate different levels of review for
extensions (see section 6.1).


4.1.4 'enum'

The 'enum' attribute syntax is an enumerated integer value that is in
the range from 1 to 2**31 - 1 (MAX).   Each value has an associated
'keyword' name.  In the definition for each attribute of this syntax
type, the full set of possible values for that attribute are listed.
This syntax type is used for attributes for which there are enum values
assigned by other standards, such as SNMP MIBs.  A number of attribute
enum values in this specification are also used for corresponding
attributes in other standards [RFC1759].  This syntax type is not used


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for attributes to which the administrator may assign values.  Section
6.1 describes how the protocol can be extended with new enum values.

Enum values are for use in the protocol.  A user interface will provide
a mapping between protocol enum values and displayable user-friendly
words and phrases which are localized to the natural language of the
user.  While the enum symbols specified in this document MAY be
displayed to users whose natural language is U.S. English, they MAY be
mapped to other U.S. English words for U.S. English users, since the
user interface is outside the scope of this document.

Note: SNMP MIBs use '2' for 'unknown' which corresponds to the IPP "out-
of-band" value 'unknown'.  See the description of the "out-of-band"
values at the beginning of Section 4.1.  Therefore, attributes of type
'enum' start at '3'.

Note:  This document uses "type1", "type2", and "type3" prefixes to the
"enum" basic syntax to indicate different levels of review for
extensions (see section 6.1).


4.1.5 'uri'

The 'uri' attribute syntax is any valid Uniform Resource Identifier or
URI [RFC2396].  Most often, URIs are simply Uniform Resource Locators or
URLs.  The maximum length of URIs used as values of IPP attributes is
1023 octets.  Although most other IPP attribute syntax types allow for
only lower-cased values, this attribute syntax type conforms to the
case-sensitive and case-insensitive rules specified in [RFC2396].  See
also [IPP-IIG] for a discussion of case in URIs.


4.1.6 'uriScheme'

The 'uriScheme' attribute syntax is a sequence of characters
representing a URI scheme according to RFC 2396 [RFC2396].  Though RFC
2396 requires that the values be case-insensitive, IPP requires all
lower case values in IPP attributes to simplify comparing by IPP clients
and Printer objects.  Standard values for this syntax type are the
following keywords:

  'http':  for HTTP schemed URIs (e.g., "http:.")
  'https':  for use with HTTPS schemed URIs (e.g., "https:...") (not on
     IETF standards track)
  'ftp': for FTP schemed URIs (e.g., "ftp:...")
  'mailto': for SMTP schemed URIs (e.g., "mailto:...")
  'file': for file schemed URIs (e.g., "file:...")


A Printer object MAY support any URI 'scheme' that has been registered
with IANA [IANA-MT]. The maximum length of URI 'scheme' values used to
represent IPP attribute values is 63 octets.





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4.1.7 'charset'

The 'charset' attribute syntax is a standard identifier for a charset.
A charset is a coded character set and encoding scheme.  Charsets are
used for labeling certain document contents and 'text' and 'name'
attribute values.  The syntax and semantics of this attribute syntax are
specified in RFC 2046 [RFC2046] and contained in the IANA character-set
Registry [IANA-CS] according to the IANA procedures [RFC2278].  Though
RFC 2046 requires that the values be case-insensitive US-ASCII, IPP
requires all lower case values in IPP attributes to simplify comparing
by IPP clients and Printer objects.  When a character-set in the IANA
registry has more than one name (alias), the name labeled as "(preferred
MIME name)", if present, MUST be used.

The maximum length of 'charset' values used to represent IPP attribute
values is 63 octets.

Some examples are:

  'utf-8':  ISO 10646 Universal Multiple-Octet Coded Character Set
     (UCS) represented as the UTF-8 [RFC2279] transfer encoding scheme
     in which US-ASCII is a subset charset.
  'us-ascii':  7-bit American Standard Code for Information Interchange
     (ASCII), ANSI X3.4-1986 [ASCII].  That standard defines US-ASCII,
     but RFC 2045 [RFC2045] eliminates most of the control characters
     from conformant usage in MIME and IPP.
  'iso-8859-1':  8-bit One-Byte Coded Character Set, Latin Alphabet Nr
     1 [ISO8859-1].  That standard defines a coded character set that is
     used by Latin languages in the Western Hemisphere and Western
     Europe.  US-ASCII is a subset charset.
  'iso-10646-ucs-2':  ISO 10646 Universal Multiple-Octet Coded
     Character Set (UCS) represented as two octets (UCS-2), with the
     high order octet of each pair coming first (so-called Big Endian
     integer).


Some attribute descriptions MAY place additional requirements on charset
values that may be used, such as REQUIRED values that MUST be supported
or additional restrictions, such as requiring that the charset have US-
ASCII as a subset charset.


4.1.8 'naturalLanguage'

The 'naturalLanguage' attribute syntax is a standard identifier for a
natural language and optionally a country.  The values for this syntax
type are defined by RFC 1766 [RFC1766].  Though RFC 1766 requires that
the values be case-insensitive US-ASCII, IPP requires all lower case to
simplify comparing by IPP clients and Printer objects.  Examples
include:

  'en':  for English
  'en-us': for US English
  'fr': for French
  'de':  for German


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The maximum length of 'naturalLanguage' values used to represent IPP
attribute values is 63 octets.


4.1.9 'mimeMediaType'

The 'mimeMediaType' attribute syntax is the Internet Media Type
(sometimes called MIME type) as defined by RFC 2046 [RFC2046] and
registered according to the procedures of RFC 2048 [RFC2048] for
identifying a document format.  The value MAY include a charset
parameter, depending on the specification of the Media Type in the IANA
Registry [IANA-MT].  Although most other IPP syntax types allow for only
lower-cased values, this syntax type allows for mixed-case values which
are case-insensitive.

Examples are:

  'text/html': An HTML document
  'text/plain': A plain text document in US-ASCII (RFC 2046 indicates
     that in the absence of the charset parameter MUST mean US-ASCII
     rather than simply unspecified) [RFC2046].
  'text/plain; charset=US-ASCII':  A plain text document in US-ASCII
     [52, 56].
  'text/plain; charset=ISO-8859-1':  A plain text document in ISO 8859-
     1 (Latin 1) [ISO8859-1].
  'text/plain; charset=utf-8':  A plain text document in ISO 10646
     represented as UTF-8 [RFC2279]
  'application/postscript':  A PostScript document [RFC2046]
  'application/vnd.hp-PCL':  A PCL document [IANA-MT] (charset escape
     sequence embedded in the document data)
  'application/pdf':  Portable Document Format - see IANA MIME Media
     Type registry
  'application/octet-stream':  (REQUIRED) Auto-sense - see below



One special type is 'application/octet-stream'.  If the Printer object
supports this value, the Printer object MUST be capable of auto-sensing
the format of the document data.  If the Printer object's default value
attribute "document-format-default" is set to 'application/octet-
stream', the Printer object not only supports auto-sensing of the
document format, but will depend on the result of applying its auto-
sensing when the client does not supply the "document-format" attribute.
If the client supplies a document format value, the Printer MUST rely on
the supplied attribute, rather than trust its auto-sensing algorithm.
To summarize:

  1. If the client does not supply a document format value, the Printer
     MUST rely on its default value setting (which may be
     'application/octet-stream' indicating an auto-sensing mechanism).
  2. If the client supplies a value other than 'application/octet-
     stream', the client is supplying valid information about the format
     of the document data and the Printer object MUST trust the client
     supplied value more than the outcome of applying an automatic
     format detection mechanism.  For example, the client may be
     requesting the printing of a PostScript file as a 'text/plain'

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     document.  The Printer object MUST print a text representation of
     the PostScript commands rather than interpret the stream of
     PostScript commands and print the result.
  3. If the client supplies a value of 'application/octet-stream', the
     client is indicating that the Printer object MUST use its auto-
     sensing mechanism on the client supplied document data whether
     auto-sensing is the Printer object's default or not.


Note:  Since the auto-sensing algorithm is probabilistic, if the client
requests both auto-sensing ("document-format" set to 'application/octet-
stream') and true fidelity ("ipp-attribute-fidelity" set to 'true'), the
Printer object might not be able to guarantee exactly what the end user
intended (the auto-sensing algorithm might mistake one document format
for another ), but it is able to guarantee that its auto-sensing
mechanism be used.

The maximum length of a 'mimeMediaType' value to represent IPP attribute
values is 255 octets.


4.1.10 'octetString'

The 'octetString' attribute syntax is a sequence of octets encoded in a
maximum of 1023 octets which is indicated in sub-section headers using
the notation: octetString(MAX).  This syntax type is used for opaque
data.


4.1.11 'boolean'

The 'boolean' attribute syntax has only two values:  'true' and 'false'.


4.1.12 'integer'

The 'integer' attribute syntax is an integer value that is in the range
from -2**31 (MIN) to 2**31 - 1 (MAX).  Each individual attribute may
specify the range constraint explicitly in sub-section headers if the
range is different from the full range of possible integer values.  For
example:  job-priority (integer(1:100)) for the "job-priority"
attribute.  However, the enforcement of that additional constraint is up
to the IPP objects, not the protocol.


4.1.13 'rangeOfInteger'

The 'rangeOfInteger' attribute syntax is an ordered pair of integers
that defines an inclusive range of integer values.  The first integer
specifies the lower bound and the second specifies the upper bound.  If
a range constraint is specified in the header description for an
attribute in this document whose attribute syntax is 'rangeOfInteger'
(i.e., 'X:Y' indicating X as a minimum value and Y as a maximum value),
then the constraint applies to both integers.




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4.1.14 'dateTime'

The 'dateTime' attribute syntax is a standard, fixed length, 11 octet
representation of the "DateAndTime" syntax as defined in RFC 1903
[RFC1903].  RFC 1903 also identifies an 8 octet representation of a
"DateAndTime" value, but IPP objects MUST use the 11 octet
representation.  A user interface will provide a mapping between
protocol dateTime values and displayable user-friendly words or
presentation values and phrases  which are localized to the natural
language and date format of the user.


4.1.15 'resolution'

The 'resolution' attribute syntax specifies a two-dimensional resolution
in the indicated units.  It consists of 3 values: a cross feed direction
resolution (positive integer value), a feed direction resolution
(positive integer value), and a units value.  The semantics of these
three components are taken from the Printer MIB [RFC1759] suggested
values.  That is, the cross feed direction component resolution
component is the same as the prtMarkerAddressabilityXFeedDir object in
the Printer MIB, the feed direction component resolution component is
the same as the prtMarkerAddressabilityFeedDir in the Printer MIB, and
the units component is the same as the prtMarkerAddressabilityUnit
object in the Printer MIB (namely, '3' indicates dots per inch and '4'
indicates dots per centimeter).  All three values MUST be present even
if the first two values are the same.  Example:  '300', '600', '3'
indicates a 300 dpi cross-feed direction resolution, a 600 dpi feed
direction resolution, since a '3' indicates dots per inch (dpi).


4.1.16 '1setOf  X'

The '1setOf  X' attribute syntax is 1 or more values of attribute syntax
type X.  This syntax type is used for multi-valued attributes.   The
syntax type is called '1setOf' rather than just 'setOf' as a reminder
that the set of values MUST NOT be empty (i.e., a set of size 0).  Sets
are normally unordered.  However each attribute description of this type
may specify that the values MUST be in a certain order for that
attribute.


4.2 Job Template Attributes


Job Template attributes describe job processing behavior.  Support for
Job Template attributes by a Printer object is OPTIONAL (see section
13.2.3 for a description of support for OPTIONAL attributes).  Also,
clients OPTIONALLY supply Job Template attributes in create requests.

Job Template attributes conform to the following rules.  For each Job
Template attribute called "xxx":

  1. If the Printer object supports "xxx" then it MUST support both a
     "xxx-default" attribute (unless there is a "No" in the table below)
     and a "xxx-supported" attribute.  If the Printer object doesn't


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     support "xxx", then it MUST support neither an "xxx-default"
     attribute nor an "xxx-supported" attribute, and it MUST treat an
     attribute "xxx" supplied by a client as unsupported.  An attribute
     "xxx" may be supported for some document formats and not supported
     for other document formats.  For example, it is expected that a
     Printer object would only support "orientation-requested" for some
     document formats (such as 'text/plain' or 'text/html') but not
     others (such as 'application/postscript').

  2. "xxx" is OPTIONALLY supplied by the client in a create request.
     If "xxx" is supplied, the client is indicating a desired job
     processing behavior for this Job.  When "xxx" is not supplied, the
     client is indicating that the Printer object apply its default job
     processing behavior at job processing time if the document content
     does not contain an embedded instruction indicating an xxx-related
     behavior.

     Note: Since an administrator MAY change the default value attribute
     after a Job object has been submitted but before it has been
     processed, the default value used by the Printer object at job
     processing time may be different that the default value in effect
     at job submission time.

  3. The "xxx-supported" attribute is a Printer object attribute that
     describes which job processing behaviors are supported by that
     Printer object.  A client can query the Printer object to find out
     what xxx-related behaviors are supported by inspecting the returned
     values of the "xxx-supported" attribute.

     Note: The "xxx" in each "xxx-supported" attribute name is singular,
     even though an "xxx-supported" attribute usually has more than one
     value, such as "job-sheet-supported", unless the "xxx" Job Template
     attribute is plural, such as "finishings" or "sides".  In such
     cases the "xxx-supported" attribute names are: "finishings-
     supported" and "sides-supported".

  4. The "xxx-default" default value attribute describes what will be
     done at job processing time when no other job processing
     information is supplied by the client (either explicitly as an IPP
     attribute in the create request or implicitly as an embedded
     instruction within the document data).


If an application wishes to present an end user with a list of supported
values from which to choose, the application SHOULD query the Printer
object for its supported value attributes.  The application SHOULD also
query the default value attributes.  If the application then limits
selectable values to only those value that are supported, the
application can guarantee that the values supplied by the client in the
create request all fall within the set of supported values at the
Printer.  When querying the Printer, the client MAY enumerate each
attribute by name in the Get-Printer-Attributes Request, or the client
MAY just name the "job-template" group in order to get the complete set
of supported attributes (both supported and default attributes).


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The "finishings" attribute is an example of a Job Template attribute.
It can take on a set of values such as 'staple', 'punch', and/or
'cover'.  A client can query the Printer object for the "finishings-
supported" attribute and the "finishings-default" attribute.  The
supported attribute contains a set of supported values.  The default
value attribute contains the finishing value(s) that will be used for a
new Job if the client does not supply a "finishings" attribute in the
create request and the document data does not contain any corresponding
finishing instructions.  If the client does supply the "finishings"
attribute in the create request, the IPP object validates the value or
values to make sure that they are a subset of the supported values
identified in the Printer object's "finishings-supported" attribute.
See section 3.2.1.2.

The table below summarizes the names and relationships for all Job
Template attributes. The first column of the table (labeled "Job
Attribute") shows the name and syntax for each Job Template attribute in
the Job object. These are the attributes that can optionally be supplied
by the client in a create request.   The last two columns (labeled
"Printer: Default Value Attribute" and "Printer: Supported Values
Attribute") shows the name and syntax for each Job Template attribute in
the Printer object (the default value attribute and the supported values
attribute).  A "No" in the table means the Printer MUST NOT support the
attribute (that is, the attribute is simply not applicable).  For
brevity in the table, the 'text' and 'name' entries do not show the
maximum length for each attribute.





























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  +===================+======================+======================+
  | Job Attribute     |Printer: Default Value|  Printer: Supported  |
  |                   |   Attribute          |   Values Attribute   |
  +===================+======================+======================+
  | job-priority      | job-priority-default |job-priority-supported|
  | (integer 1:100)   | (integer 1:100)      |(integer 1:100)       |
  +-------------------+----------------------+----------------------+
  | job-hold-until    | job-hold-until-      |job-hold-until-       |
  | (type3 keyword |  |  default             | supported            |
  |    name)          |  (type3 keyword |    |(1setOf               |
  |                   |    name)             | type3 keyword | name)|
  +-------------------+----------------------+----------------------+
  | job-sheets        | job-sheets-default   |job-sheets-supported  |
  | (type3 keyword |  | (type3 keyword |     |(1setOf               |
  |    name)          |    name)             | type3 keyword | name)|
  +-------------------+----------------------+----------------------+
  |multiple-document- |multiple-document-    |multiple-document-    |
  | handling          | handling-default     |handling-supported    |
  | (type2 keyword)   | (type2 keyword)      |(1setOf type2 keyword)|
  +-------------------+----------------------+----------------------+
  | copies            | copies-default       | copies-supported     |
  | (integer (1:MAX)) | (integer (1:MAX))    | (rangeOfInteger      |
  |                   |                      |       (1:MAX))       |
  +-------------------+----------------------+----------------------+
  | finishings        | finishings-default   | finishings-supported |
  |(1setOf type2 enum)|(1setOf type2 enum)   |(1setOf type2 enum)   |
  +-------------------+----------------------+----------------------+
  | page-ranges       | No                   | page-ranges-         |
  | (1setOf           |                      | supported (boolean)  |
  |   rangeOfInteger  |                      |                      |
  |        (1:MAX))   |                      |                      |
  +-------------------+----------------------+----------------------+
  | sides             | sides-default        | sides-supported      |
  | (type2 keyword)   | (type2 keyword)      |(1setOf type2 keyword)|
  +-------------------+----------------------+----------------------+
  | number-up         | number-up-default    | number-up-supported  |
  | (integer (1:MAX)) | (integer (1:MAX))    |(1setOf integer       |
  |                   |                      | (1:MAX) |            |
  |                   |                      |  rangeOfInteger      |
  |                   |                      |   (1:MAX))           |
  +-------------------+----------------------+----------------------+
  | orientation-      |orientation-requested-|orientation-requested-|
  |  requested        |  default             |  supported           |
  |   (type2 enum)    |  (type2 enum)        |  (1setOf type2 enum) |
  +-------------------+----------------------+----------------------+
  | media             | media-default        | media-supported      |
  | (type3 keyword |  | (type3 keyword |     |(1setOf               |
  |    name)          |    name)             | type3 keyword | name)|
  |                   |                      |                      |
  |                   |                      | media-ready          |
  |                   |                      |(1setOf               |
  |                   |                      | type3 keyword | name)|
  +-------------------+----------------------+----------------------+
  | printer-resolution| printer-resolution-  | printer-resolution-  |

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  | (resolution)      |  default             | supported            |
  |                   | (resolution)         |(1setOf resolution)   |
  +-------------------+----------------------+----------------------+
  | print-quality     | print-quality-default| print-quality-       |
  | (type2 enum)      | (type2 enum)         | supported            |
  |                   |                      |(1setOf type2 enum)   |
  +-------------------+----------------------+----------------------+



4.2.1 job-priority (integer(1:100))

This attribute specifies a priority for scheduling the Job. A higher
value specifies a higher priority. The value 1 indicates the lowest
possible priority. The value 100 indicates the highest possible
priority.  Among those jobs that are ready to print, a Printer MUST
print all jobs with a priority value of n before printing those with a
priority value of n-1 for all n.

If the Printer object supports this attribute, it MUST always support
the full range from 1 to 100.  No administrative restrictions are
permitted.  This way an end-user can always make full use of the entire
range with any Printer object.  If privileged jobs are implemented
outside IPP/1.1, they MUST have priorities higher than 100, rather than
restricting the range available to end-users.

If the client does not supply this attribute and this attribute is
supported by the Printer object, the Printer object MUST use the value
of the Printer object's "job-priority-default" at job submission time
(unlike most Job Template attributes that are used if necessary at job
processing time).

The syntax for the "job-priority-supported" is also integer(1:100).
This single integer value indicates the number of priority levels
supported.  The Printer object MUST take the value supplied by the
client and map it to the closest integer in a sequence of n integers
values that are evenly distributed over the range from 1 to 100 using
the formula:

     roundToNearestInt((100x+50)/n)

where n is the value of "job-priority-supported" and x ranges from 0
through n-1.

For example, if n=1 the sequence of values is 50;  if n=2, the sequence
of values is:  25 and 75;  if n = 3, the sequence of values is:  17, 50
and 83;  if n = 10, the sequence of values is: 5, 15, 25, 35, 45, 55,
65, 75, 85, and 95;  if n = 100, the sequence of values is:  1, 2, 3, .
100.

If the value of the Printer object's "job-priority-supported" is 10 and
the client supplies values in the range 1 to 10, the Printer object maps
them to 5, in the range 11 to 20, the Printer object maps them to 15,
etc.

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4.2.2 job-hold-until (type3 keyword | name (MAX))

This attribute specifies the named time period during which the Job MUST
become a candidate for printing.

Standard keyword values for named time periods are:

  'no-hold': immediately, if there are not other reasons to hold the
     job
  'indefinite':  - the job is held indefinitely, until a client
     performs a Release-Job (section 3.3.6)
  'day-time': during the day
  'evening': evening
  'night': night
  'weekend': weekend
  'second-shift': second-shift (after close of business)
  'third-shift': third-shift (after midnight)


An administrator MUST associate allowable print times with a named time
period (by means outside the scope of this IPP/1.1 document).  An
administrator is encouraged to pick names that suggest the type of time
period. An administrator MAY define additional values using the 'name'
or 'keyword' attribute syntax, depending on implementation.

If the value of this attribute specifies a time period that is in the
future, the Printer MUST add the 'job-hold-until-specified' value to the
job's "job-state-reasons" attribute, move the job to the 'pending-held'
state, and MUST NOT schedule the job for printing until the specified
time-period arrives.  When the specified time period arrives, the
Printer MUST remove the 'job-hold-until-specified' value from the job's
"job-state-reason" attribute and, if there are no other job state
reasons that keep the job in the 'pending-held' state, the Printer MUST
consider the job as a candidate for processing by moving the job to the
'pending' state.

If this job attribute value is the named value 'no-hold', or the
specified time period has already started, the job MUST be a candidate
for processing immediately.

If the client does not supply this attribute and this attribute is
supported by the Printer object, the Printer object MUST use the value
of the Printer object's "job-hold-until-default" at job submission time
(unlike most Job Template attributes that are used if necessary at job
processing time).


4.2.3 job-sheets (type3 keyword | name(MAX))

This attribute determines which job start/end sheet(s), if any, MUST be
printed with a job.

Standard keyword values are:

  'none': no job sheet is printed


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  'standard': one or more site specific standard job sheets are
     printed, e.g. a single start sheet or both start and end sheet is
     printed


An administrator MAY define additional values using the 'name' or
'keyword' attribute syntax, depending on implementation.

Note: The effect of this attribute on jobs with multiple documents MAY
be affected by the "multiple-document-handling" job attribute (section
4.2.4), depending on the job sheet semantics.


4.2.4 multiple-document-handling (type2 keyword)

This attribute is relevant only if a job consists of two or more
documents. The attribute controls finishing operations and the placement
of one or more print-stream pages into impressions and onto media
sheets.  When the value of the "copies" attribute exceeds 1, it also
controls the order in which the copies that result from processing the
documents are produced. For the purposes of this explanations, if "a"
represents an instance of document data, then the result of processing
the data in document "a" is a sequence of media sheets represented by
"a(*)".

Standard keyword values are:

  'single-document': If a Job object has multiple documents, say, the
     document data is called a and b, then the result of processing all
     the document data (a and then b) MUST be treated as a single
     sequence of media sheets for finishing operations; that is,
     finishing would be performed on the concatenation of the sequences
     a(*),b(*).  The Printer object MUST NOT force the data in each
     document instance to be formatted onto a new print-stream page, nor
     to start a new impression on a new media sheet. If more than one
     copy is made, the ordering of the sets of media sheets resulting
     from processing the document data MUST be a(*), b(*), a(*), b(*),
     ..., and the Printer object MUST force each copy (a(*),b(*)) to
     start on a new media sheet.
  'separate-documents-uncollated-copies': If a Job object has multiple
     documents, say, the document data is called a and b, then the
     result of processing the data in each document instance MUST be
     treated as a single sequence of media sheets for finishing
     operations; that is, the sets a(*) and b(*) would each be finished
     separately. The Printer object MUST force each copy of the result
     of processing the data in a single document to start on a new media
     sheet. If more than one copy is made, the ordering of the sets of
     media sheets resulting from processing the document data MUST be
     a(*), a(*), ..., b(*), b(*) ... .
  'separate-documents-collated-copies': If a Job object has multiple
     documents, say, the document data is called a and b, then the
     result of processing the data in each document instance MUST be
     treated as a single sequence of media sheets for finishing
     operations; that is, the sets a(*) and b(*) would each be finished
     separately. The Printer object MUST force each copy of the result


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     of processing the data in a single document to start on a new media
     sheet.  If more than one copy is made, the ordering of the sets of
     media sheets resulting from processing the document data MUST be
     a(*), b(*), a(*), b(*), ... .
  'single-document-new-sheet':  Same as 'single-document', except that
     the Printer object MUST ensure that the first impression of each
     document instance in the job is placed on a new media sheet.  This
     value allows multiple documents to be stapled together with a
     single staple where each document starts on a new sheet.


The 'single-document' value is the same as 'separate-documents-collated-
copies' with respect to ordering of print-stream pages, but not media
sheet generation, since 'single-document' will put the first page of the
next document on the back side of a sheet if an odd number of pages have
been produced so far for the job, while 'separate-documents-collated-
copies' always forces the next document or document copy on to a new
sheet.  In addition, if the "finishings" attribute specifies 'staple',
then with 'single-document', documents a and b are stapled together as a
single document with no regard to new sheets, with 'single-document-new-
sheet', documents a and b are stapled together as a single document, but
document b starts on a new sheet, but with 'separate-documents-
uncollated-copies' and 'separate-documents-collated-copies', documents a
and b are stapled separately.

Note: None of these values provide means to produce uncollated sheets
within a document, i.e., where multiple copies of sheet n are produced
before sheet n+1 of the same document.

The relationship of this attribute and the other attributes that control
document processing is described in section 16.3.


4.2.5 copies (integer(1:MAX))

This attribute specifies the number of copies to be printed.

On many devices the supported number of collated copies will be limited
by the number of physical output bins on the device, and may be
different from the number of uncollated copies which can be supported.

Note: The effect of this attribute on jobs with multiple documents is
controlled by the "multiple-document-handling" job attribute (section
4.2.4) and the relationship of this attribute and the other attributes
that control document processing is described in section 16.3.


4.2.6 finishings (1setOf type2 enum)

This attribute identifies the finishing operations that the Printer uses
for each copy of each printed document in the Job. For Jobs with
multiple documents, the "multiple-document-handling" attribute
determines what constitutes a "copy" for purposes of finishing.

Standard enum values are:


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  Value  Symbolic Name and Description

  '3'    'none':  Perform no finishing
  '4'    'staple':  Bind the document(s) with one or more staples. The
               exact number and placement of the staples is site-
               defined.
  '5'    'punch':  This value indicates that holes are required in the
               finished document. The exact number and placement of the
               holes is site-defined  The punch specification MAY be
               satisfied (in a site- and implementation-specific manner)
               either by drilling/punching, or by substituting pre-
               drilled media.
  '6'    'cover':  This value is specified when it is desired to select
               a non-printed (or pre-printed) cover for the document.
               This does not supplant the specification of a printed
               cover (on cover stock medium) by the document itself.
  '7'    'bind':  This value indicates that a binding is to be applied
               to the document; the type and placement of the binding is
               site-defined.

  '8'    'saddle-stitch':  Bind the document(s) with one or more
               staples (wire stitches) along the middle fold.  The exact
               number and placement of the staples and the middle fold
               is implementation and/or site-defined.
  '9'    'edge-stitch':  Bind the document(s) with one or more staples
               (wire stitches) along one edge.  The exact number and
               placement of the staples is implementation and/or site-
               defined.
  '10'-'19'   reserved for future generic finishing enum values.

The following values are more specific; they indicate a corner or an
edge as if the document were a portrait document (see below):

  '20'   'staple-top-left':  Bind the document(s) with one or more
               staples in the top left corner.
  '21'   'staple-bottom-left':  Bind the document(s) with one or more
               staples in the bottom left corner.
  '22'   'staple-top-right':  Bind the document(s) with one or more
               staples in the top right corner.
  '23'   'staple-bottom-right':  Bind the document(s) with one or more
               staples in the bottom right corner.
  '24'   'edge-stitch-left':  Bind the document(s) with one or more
               staples (wire stitches) along the left edge.  The exact
               number and placement of the staples is implementation
               and/or site-defined.
  '25'   'edge-stitch-top':  Bind the document(s) with one or more
               staples (wire stitches) along the top edge.  The exact
               number and placement of the staples is implementation
               and/or site-defined.
  '26'   'edge-stitch-right':  Bind the document(s) with one or more
               staples (wire stitches) along the right edge.  The exact
               number and placement of the staples is implementation
               and/or site-defined.
  '27'   'edge-stitch-bottom':  Bind the document(s) with one or more
               staples (wire stitches) along the bottom edge.  The exact

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               number and placement of the staples is implementation
               and/or site-defined.
  '28'   'staple-dual-left':  Bind the document(s) with two staples
               (wire stitches) along the left edge assuming a portrait
               document (see above).
  '29'   'staple-dual-top':  Bind the document(s) with two staples
               (wire stitches) along the top edge assuming a portrait
               document (see above).
  '30'   'staple-dual-right':  Bind the document(s) with two staples
               (wire stitches) along the right edge assuming a portrait
               document (see above).
  '31'   'staple-dual-bottom':  Bind the document(s) with two staples
               (wire stitches) along the bottom edge assuming a portrait
               document (see above).

The 'staple-xxx' values are specified with respect to the document as if
the document were a portrait document.  If the document is actually a
landscape or a reverse-landscape document, the client supplies the
appropriate transformed value.  For example, to position a staple in the
upper left hand corner of a landscape document when held for reading,
the client supplies the 'staple-bottom-left' value (since landscape is
defined as a +90 degree rotation from portrait, i.e., anti-clockwise).
On the other hand, to position a staple in the upper left hand corner of
a reverse-landscape document when held for reading, the client supplies
the 'staple-top-right' value (since reverse-landscape is defined as a -
90 degree rotation from portrait, i.e., clockwise).

The angle (vertical, horizontal, angled) of each staple with respect to
the document depends on the implementation which may in turn depend on
the value of the attribute.

Note: The effect of this attribute on jobs with multiple documents is
controlled by the "multiple-document-handling" job attribute (section
4.2.4) and the relationship of this attribute and the other attributes
that control document processing is described in section 16.3.

If the client supplies a value of 'none' along with any other
combination of values, it is the same as if only that other combination
of values had been supplied (that is the 'none' value has no effect).


4.2.7 page-ranges (1setOf rangeOfInteger (1:MAX))

This attribute identifies the range(s) of print-stream pages that the
Printer object uses for each copy of each document which are to be
printed.  Nothing is printed for any pages identified that do not exist
in the document(s).  Ranges MUST be in ascending order, for example: 1-
3, 5-7, 15-19 and MUST NOT overlap, so that a non-spooling Printer
object can process the job in a single pass.  If the ranges are not
ascending or are overlapping, the IPP object MUST reject the request and
return the 'client-error-bad-request' status code.  The attribute is
associated with print-stream pages not application-numbered pages (for
example, the page numbers found in the headers and or footers for
certain word processing applications).


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For Jobs with multiple documents, the "multiple-document-handling"
attribute determines what constitutes a "copy" for purposes of the
specified page range(s).  When "multiple-document-handling" is 'single-
document', the Printer object MUST apply each supplied page range once
to the concatenation of the print-stream pages.  For example, if there
are 8 documents of 10 pages each, the page-range '41:60' prints the
pages in the 5th and 6th documents as a single document and none of the
pages of the other documents are printed.  When "multiple-document-
handling" is 'separate-document-uncollated-copies' or 'separate-
document-collated-copies', the Printer object MUST apply each supplied
page range repeatedly to each document copy.  For the same job, the
page-range '1:3, 10:10' would print the first 3 pages and the 10th page
of each of the 8 documents in the Job, as 8 separate documents.

In most cases, the exact pages to be printed will be generated by a
device driver and this attribute would not be required.  However, when
printing an archived document which has already been formatted, the end
user may elect to print just a subset of the pages contained in the
document.  In this case, if page-range = n.m is specified, the first
page to be printed will be page n. All subsequent pages of the document
will be printed through and including page m.

"page-ranges-supported" is a boolean value indicating whether or not the
printer is capable of supporting the printing of page ranges.  This
capability may differ from one PDL to another. There is no "page-ranges-
default" attribute.  If the "page-ranges" attribute is not supplied by
the client, all pages of the document will be printed.

Note: The effect of this attribute on jobs with multiple documents is
controlled by the "multiple-document-handling" job attribute (section
4.2.4) and the relationship of this attribute and the other attributes
that control document processing is described in section 16.3.


4.2.8 sides (type2 keyword)

This attribute specifies how print-stream pages are to be imposed upon
the sides of an instance of a selected medium, i.e., an impression.

The standard keyword values are:

  'one-sided': imposes each consecutive print-stream page upon the same
     side of consecutive media sheets.
  'two-sided-long-edge': imposes each consecutive pair of print-stream
     pages upon front and back sides of consecutive media sheets, such
     that the orientation of each pair of print-stream pages on the
     medium would be correct for the reader as if for binding on the
     long edge.  This imposition is sometimes called 'duplex' or 'head-
     to-head'.
  'two-sided-short-edge': imposes each consecutive pair of print-stream
     pages upon front and back sides of consecutive media sheets, such
     that the orientation of each pair of print-stream pages on the
     medium would be correct for the reader as if for binding on the
     short edge.  This imposition is sometimes called 'tumble' or 'head-
     to-toe'.

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'two-sided-long-edge', 'two-sided-short-edge', 'tumble', and 'duplex'
all work the same for portrait or landscape.  However 'head-to-toe' is
'tumble' in portrait but 'duplex' in landscape.  'head-to-head' also
switches between 'duplex' and 'tumble' when using portrait and landscape
modes.

Note: The effect of this attribute on jobs with multiple documents is
controlled by the "multiple-document-handling" job attribute (section
4.2.4) and the relationship of this attribute and the other attributes
that control document processing is described in section 16.3.


4.2.9 number-up (integer(1:MAX))

This attribute specifies the number of print-stream pages to impose upon
a single side of an instance of a selected medium.  For example, if the
value is:

  Value  Description

  '1'    the Printer MUST place one print-stream page on a single side
               of an instance of the selected medium (MAY add some sort
               of translation, scaling, or rotation).
  '2'    the Printer MUST place two print-stream pages on a single side
               of an instance of the selected medium (MAY add some sort
               of translation, scaling, or rotation).
  '4'    the Printer MUST place four print-stream pages on a single
               side of an instance of the selected medium (MAY add some
               sort of translation, scaling, or rotation).


This attribute primarily controls the translation, scaling and rotation
of print-stream pages.

Note: The effect of this attribute on jobs with multiple documents is
controlled by the "multiple-document-handling" job attribute (section
4.2.4) and the relationship of this attribute and the other attributes
that control document processing is described in section 16.3.


4.2.10 orientation-requested (type2 enum)

This attribute indicates the desired orientation for printed print-
stream pages; it does not describe the orientation of the client-
supplied print-stream pages.

For some document formats (such as 'application/postscript'), the
desired orientation of the print-stream pages is specified within the
document data.  This information is generated by a device driver prior
to the submission of the print job.  Other document formats (such as
'text/plain') do not include the notion of desired orientation within
the document data.  In the latter case it is possible for the Printer
object to bind the desired orientation to the document data after it has
been submitted.  It is expected that a Printer object would only support


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"orientations-requested" for some document formats (e.g., 'text/plain'
or 'text/html') but not others (e.g., 'application/postscript').  This
is no different than any other Job Template attribute since section 4.2,
item 1, points out that a Printer object may support or not support any
Job Template attribute based on the document format supplied by the
client.  However, a special mention is made here since it is very likely
that a Printer object will support "orientation-requested" for only a
subset of the supported document formats.

Standard enum values are:

  Value  Symbolic Name and Description

  '3'    'portrait':  The content will be imaged across the short edge
               of the medium.
  '4'    'landscape':  The content will be imaged across the long edge
               of the medium.  Landscape is defined to be a rotation of
               the print-stream page to be imaged by +90 degrees with
               respect to the medium (i.e. anti-clockwise) from the
               portrait orientation.  Note:  The +90 direction was
               chosen because simple finishing on the long edge is the
               same edge whether portrait or landscape
  '5'    'reverse-landscape':  The content will be imaged across the
               long edge of the medium.  Reverse-landscape is defined to
               be a rotation of the print-stream page to be imaged by -
               90 degrees with respect to the medium (i.e. clockwise)
               from the portrait orientation.  Note: The 'reverse-
               landscape' value was added because some applications
               rotate landscape -90 degrees from portrait, rather than
               +90 degrees.
  '6'    'reverse-portrait':  The content will be imaged across the
               short edge of the medium.  Reverse-portrait is defined to
               be a rotation of the print-stream page to be imaged by
               180 degrees with respect to the medium from the portrait
               orientation.  Note: The 'reverse-portrait' value was
               added for use with the "finishings" attribute in cases
               where the opposite edge is desired for finishing a
               portrait document on simple finishing devices that have
               only one finishing position.  Thus a 'text'/plain'
               portrait document can be stapled "on the right" by a
               simple finishing device as is common use with some middle
               eastern languages such as Hebrew.


Note: The effect of this attribute on jobs with multiple documents is
controlled by the "multiple-document-handling" job attribute (section
4.2.4) and the relationship of this attribute and the other attributes
that control document processing is described in section 16.3.


4.2.11 media (type3 keyword | name(MAX))

This attribute identifies the medium that the Printer uses for all
impressions of the Job.



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The values for "media" include medium-names, medium-sizes, input-trays
and electronic forms so that one attribute specifies the media. If a
Printer object supports a medium name as a value of this attribute, such
a medium name implicitly selects an input-tray that contains the
specified medium.  If a Printer object supports a medium size as a value
of this attribute, such a medium size implicitly selects a medium name
that in turn implicitly selects an input-tray that contains the medium
with the specified size.  If a Printer object supports an input-tray as
the value of this attribute, such an input-tray implicitly selects the
medium that is in that input-tray at the time the job prints.  This case
includes manual-feed input-trays.  If a Printer object supports an
electronic form as the value of this attribute, such an electronic form
implicitly selects a medium-name that in turn implicitly selects an
input-tray that contains the medium specified by the electronic form.
The electronic form also implicitly selects an image that the Printer
MUST merge with the document data as its prints each page.

Standard keyword values are (taken from ISO DPA and the Printer MIB) and
are listed in section 15. An administrator MAY define additional values
using the 'name' or 'keyword' attribute syntax, depending on
implementation.

There is also an additional Printer attribute named "media-ready" which
differs from "media-supported" in that legal values only include the
subset of "media-supported" values that are physically loaded and ready
for printing with no operator intervention required.  If an IPP object
supports "media-supported", it NEED NOT support "media-ready".

The relationship of this attribute and the other attributes that control
document processing is described in section 16.3.


4.2.12 printer-resolution (resolution)

This attribute identifies the resolution that Printer uses for the Job.


4.2.13 print-quality (type2 enum)

This attribute specifies the print quality that the Printer uses for the
Job.

The standard enum values are:

  Value  Symbolic Name and Description

  '3'    'draft': lowest quality available on the printer
  '4'    'normal': normal or intermediate quality on the printer
  '5'    'high': highest quality available on the printer








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4.3 Job Description Attributes


The attributes in this section form the attribute group called "job-
description".  The following table summarizes these attributes.  The
third column indicates whether the attribute is a REQUIRED attribute
that MUST be supported by Printer objects.  If it is not indicated as
REQUIRED, then it is OPTIONAL.  The maximum size in octets for 'text'
and 'name' attributes is indicated in parenthesizes.















































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+----------------------------+----------------------+----------------+
|      Attribute             |     Syntax           |   REQUIRED?    |
+----------------------------+----------------------+----------------+
| job-uri                    | uri                  |  REQUIRED      |
+----------------------------+----------------------+----------------+
| job-id                     | integer(1:MAX)       |  REQUIRED      |
+----------------------------+----------------------+----------------+
| job-printer-uri            | uri                  |  REQUIRED      |
+----------------------------+----------------------+----------------+
| job-more-info              | uri                  |                |
+----------------------------+----------------------+----------------+
| job-name                   | name (MAX)           |  REQUIRED      |
+----------------------------+----------------------+----------------+
| job-originating-user-name  | name (MAX)           |  REQUIRED      |
+----------------------------+----------------------+----------------+
| job-state                  | type1 enum           |  REQUIRED      |
+----------------------------+----------------------+----------------+
| job-state-reasons          | 1setOf type2 keyword |                |
+----------------------------+----------------------+----------------+
| job-state-message          | text (MAX)           |                |
+----------------------------+----------------------+----------------+
| number-of-documents        | integer (0:MAX)      |                |
+----------------------------+----------------------+----------------+
| output-device-assigned     | name (127)           |                |
+----------------------------+----------------------+----------------+
| time-at-creation           | integer (0:MAX)      |                |
+----------------------------+----------------------+----------------+
| time-at-processing         | integer (0:MAX)      |                |
+----------------------------+----------------------+----------------+
| time-at-completed          | integer (0:MAX)      |                |
+----------------------------+----------------------+----------------+
| number-of-intervening-jobs | integer (0:MAX)      |                |
+----------------------------+----------------------+----------------+
| job-message-from-operator  | text (127)           |                |
+----------------------------+----------------------+----------------+
| job-k-octets               | integer (0:MAX)      |                |
+----------------------------+----------------------+----------------+
| job-impressions            | integer (0:MAX)      |                |
+----------------------------+----------------------+----------------+
| job-media-sheets           | integer (0:MAX)      |                |
+----------------------------+----------------------+----------------+
| job-k-octets-processed     | integer (0:MAX)      |                |
+----------------------------+----------------------+----------------+
| job-impressions-completed  | integer (0:MAX)      |                |
+----------------------------+----------------------+----------------+
| job-media-sheets-completed | integer (0:MAX)      |                |
+----------------------------+----------------------+----------------+
| attributes-charset         | charset              |  REQUIRED      |
+----------------------------+----------------------+----------------+
| attributes-natural-language| naturalLanguage      |  REQUIRED      |
+----------------------------+----------------------+----------------+




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4.3.1 job-uri (uri)

This REQUIRED attribute contains the URI for the job.  The Printer
object, on receipt of a new job, generates a URI which identifies the
new Job.  The Printer object returns the value of the "job-uri"
attribute as part of the response to a create request.  The precise
format of a Job URI is implementation dependent.  If the Printer object
supports more than one URI and there is some relationship between the
newly formed Job URI and the Printer object's URI, the Printer object
uses the Printer URI supplied by the client in the create request.  For
example, if the create request comes in over a secure channel, the new
Job URI MUST use the same secure channel.  This can be guaranteed
because the Printer object is responsible for generating the Job URI and
the Printer object is aware of its security configuration and policy as
well as the Printer URI used in the create request.

For a description of this attribute and its relationship to "job-id" and
"job-printer-uri" attribute, see the discussion in section 2.4 on
"Object Identity".


4.3.2 job-id (integer(1:MAX))

This REQUIRED attribute contains the ID of the job.  The Printer, on
receipt of a new job, generates an ID which identifies the new Job on
that Printer.  The Printer returns the value of the "job-id" attribute
as part of the response to a create request.  The 0 value is not
included to allow for compatibility with SNMP index values which also
cannot be 0.

For a description of this attribute and its relationship to "job-uri"
and "job-printer-uri" attribute, see the discussion in section 2.4 on
"Object Identity".


4.3.3 job-printer-uri (uri)

This REQUIRED attribute identifies the Printer object that created this
Job object.  When a Printer object creates a Job object, it populates
this attribute with the Printer object URI that was used in the create
request.  This attribute permits a client to identify the Printer object
that created this Job object when only the Job object's URI is available
to the client.  The client queries the creating Printer object to
determine which languages, charsets, operations, are supported for this
Job.

For a description of this attribute and its relationship to "job-uri"
and "job-id" attribute, see the discussion in section 2.4 on "Object
Identity".







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4.3.4 job-more-info (uri)

Similar to "printer-more-info", this attribute contains the URI
referencing some resource with more information about this Job object,
perhaps an HTML page containing information about the Job.


4.3.5 job-name (name(MAX))

This REQUIRED attribute is the name of the job.  It is a name that is
more user friendly than the "job-uri" attribute value.  It does not need
to be unique between Jobs.  The Job's "job-name" attribute is set to the
value supplied by the client in the "job-name" operation attribute in
the create request (see Section 3.2.1.1).   If, however, the "job-name"
operation attribute is not supplied by the client in the create request,
the Printer object, on creation of the Job, MUST generate a name.  The
printer SHOULD generate the value of the Job's "job-name" attribute from
the first of the following sources that produces a value: 1) the
"document-name" operation attribute of the first (or only) document, 2)
the "document-URI" attribute of the first (or only) document, or 3) any
other piece of Job specific and/or Document Content information.


4.3.6 job-originating-user-name (name(MAX))

This REQUIRED attribute contains the name of the end user that submitted
the print job.  The Printer object sets this attribute to the most
authenticated printable name that it can obtain from the authentication
service over which the IPP operation was received.  Only if such is not
available, does the Printer object use the value supplied by the client
in the "requesting-user-name" operation attribute of the create
operation (see Section 8).

Note:  The Printer object needs to keep an internal originating user id
of some form, typically as a credential of a principal, with the Job
object.  Since such an internal attribute is implementation-dependent
and not of interest to clients, it is not specified as a Job Description
attribute.  This originating user id is used for authorization checks
(if any) on all subsequent operation.


4.3.7 job-state (type1 enum)

This REQUIRED attribute identifies the current state of the job.  Even
though the IPP protocol defines seven values for job states (plus the
out-of-band 'unknown' value - see Section 4.1), implementations only
need to support those states which are appropriate for the particular
implementation.  In other words, a Printer supports only those job
states implemented by the output device and available to the Printer
object implementation.

Standard enum values are:

  Values Symbolic Name and Description



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  '3'    'pending':  The job is a candidate to start processing, but is
               not yet processing.

  '4'    'pending-held':  The job is not a candidate for processing for
               any number of reasons but will return to the 'pending'
               state as soon as the reasons are no longer present.  The
               job's "job-state-reason" attribute MUST indicate why the
               job is no longer a candidate for processing.

  '5'    'processing':  One or more of:

               1.  the job is using, or is attempting to use, one or
               more purely software processes that are analyzing,
               creating, or interpreting a PDL, etc.,
               2.  the job is using, or is attempting to use, one or
               more hardware devices that are interpreting a PDL, making
               marks on a medium, and/or performing finishing, such as
               stapling, etc.,
               3. the Printer object has made the job ready for
               printing, but the output device is not yet printing it,
               either because the job hasn't reached the output device
               or because the job is queued in the output device or some
               other spooler, awaiting the output device to print it.


               When the job is in the 'processing' state, the entire job
               state includes the detailed status represented in the
               printer's "printer-state", "printer-state-reasons", and
               "printer-state-message" attributes.

               Implementations MAY, though they NEED NOT,  include
               additional values in the job's "job-state-reasons"
               attribute to indicate the progress of the job, such as
               adding the 'job-printing' value to indicate when the
               output device is actually making marks on paper and/or
               the 'processing-to-stop-point' value to indicate that the
               IPP object is in the process of canceling or aborting the
               job.  Most implementations won't bother with this nuance.


  '6'    'processing-stopped':  The job has stopped while processing
               for any number of reasons and will return to the
               'processing' state as soon as the reasons are no longer
               present.


               The job's "job-state-reason" attribute MAY indicate why
               the job has stopped processing.  For example, if the
               output device is stopped, the 'printer-stopped' value MAY
               be included in the job's "job-state-reasons" attribute.


               Note:  When an output device is stopped, the device
               usually indicates its condition in human readable form
               locally at the device.  A client can obtain more complete
               device status remotely by querying the Printer object's


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               "printer-state", "printer-state-reasons" and "printer-
               state-message" attributes.


  '7'    'canceled':  The job has been canceled by a Cancel-Job
               operation and the Printer object has completed canceling
               the job and all job status attributes have reached their
               final values for the job.  While the Printer object is
               canceling the job, the job remains in its current state,
               but the job's "job-state-reasons" attribute SHOULD
               contain the 'processing-to-stop-point' value and one of
               the 'canceled-by-user', 'canceled-by-operator', or
               'canceled-at-device' value.  When the job moves to the
               'canceled' state, the  'processing-to-stop-point' value,
               if present, MUST be removed, but the 'canceled-by-xxx',
               if present, MUST remain.

  '8'    'aborted':  The job has been aborted by the system, usually
               while the job was in the 'processing' or 'processing-
               stopped' state and the Printer has completed aborting the
               job and all job status attributes have reached their
               final values for the job.  While the Printer object is
               aborting the job, the job remains in its current state,
               but the job's "job-state-reasons" attribute SHOULD
               contain the 'processing-to-stop-point' and 'aborted-by-
               system' values.  When the job moves to the 'aborted'
               state, the  'processing-to-stop-point' value, if present,
               MUST be removed, but the 'aborted-by-system' value, if
               present, MUST remain.

  '9'    'completed':  The job has completed successfully or with
               warnings or errors after processing and all of the job
               media sheets have been successfully stacked in the
               appropriate output bin(s) and all job status attributes
               have reached their final values for the job.  The job's
               "job-state-reasons" attribute SHOULD contain one of:
               'completed-successfully', 'completed-with-warnings', or
               'completed-with-errors' values.


The final value for this attribute MUST be one of: 'completed',
'canceled', or 'aborted' before the Printer removes the job altogether.
The length of time that jobs remain in the 'canceled', 'aborted', and
'completed' states depends on implementation.  See section 4.3.7.1.

The following figure shows the normal job state transitions.










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                                                   +----> canceled
                                                  /
    +----> pending --------> processing ---------+------> completed
    |         ^                   ^               \
--->+         |                   |                +----> aborted
    |         v                   v               /
    +----> pending-held    processing-stopped ---+


Normally a job progresses from left to right.  Other state transitions
are unlikely, but are not forbidden.  Not shown are the transitions to
the 'canceled' state from the 'pending', 'pending-held', and
'processing-stopped' states.

Jobs reach one of the three terminal states: 'completed', 'canceled', or
'aborted', after the jobs have completed all activity, including
stacking output media, after the jobs have completed all activity, and
all job status attributes have reached their final values for the job.

Note: As with all other IPP attributes, if the implementation can not
determine the correct value for this attribute, it SHOULD respond with
the out-of-band value 'unknown' (see section 4.1) rather than try to
guess at some possibly incorrect value and give the end user the wrong
impression about the state of the Job object.  For example, if the
implementation is just a gateway into some printing system that does not
provide detailed status about the print job, the IPP Job object's state
might literally be 'unknown'.


4.3.7.1 Partitioning of Job States

This section partitions the 7 job states into phases:  Job Not
Completed, Job Retention, Job History, and Job Removal.  This section
also explains the 'job-restartable' value of the "job-state-reasons" Job
Description attribute for use with the Restart-Job operation.

Job Not Completed:  When a job is in the 'pending', 'pending-held',
'processing', or 'processing-stopped' states, the job is not completed.

Job Retention:  When a job enters one of the three terminal job states:
'completed', 'canceled', or 'aborted', the IPP Printer object MAY
"retain" the job in a restartable condition for an implementation-
defined time period.  This time period MAY be zero seconds and MAY
depend on the terminal job state.  This phase is called Job Retention.
While in the Job Retention phase, the job's document data is retained
and a client may restart the job using the Restart-Job operation.  If
the IPP object supports the "job-state-reasons" attribute and the
Restart-Job operation, then it SHOULD indicate that the job is
restartable by adding the 'job-restartable' value to the job's "job-
state-reasons" attribute (see Section 4.3.8) during the Job Retention
phase.

Job History:  After the Job Retention phase expires for a job, the
Printer object deletes the document data for the job and the job becomes
part of the Job History.  The Printer object MAY also delete any number
of the job attributes.  Since the job is no longer restartable, the

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Printer object MUST remove the 'job-restartable' value from the job's
"job-state-reasons" attribute, if present.

Job Removal:  After the job has remained in the Job History for an
implementation-defined time, such as when the number of jobs exceeds a
fixed number or after a fixed time period (which MAY be zero seconds),
the IPP Printer removes the job from the system.

Using the Get-Jobs operation and supplying the 'not-completed' value for
the "which-jobs" operation attribute, a client is requesting jobs in the
Job Not Completed phase.  Using the Get-Jobs operation and supplying the
'completed' value for the "which-jobs" operation attribute, a client is
requesting jobs in the Job Retention and Job History phases.  Using the
Get-Job-Attributes operation, a client is requesting a job in any phase
except Job Removal.  After Job Removal, the Get-Job-Attributes and Get-
Jobs operations no longer are capable of returning any information about
a job.


4.3.8 job-state-reasons (1setOf  type2 keyword)

This attribute provides additional information about the job's current
state, i.e., information that augments the value of the job's "job-
state" attribute.

Implementation of these values is OPTIONAL, i.e., a Printer NEED NOT
implement them, even if (1) the output device supports the functionality
represented by the reason and (2) is available to the Printer object
implementation.  These values MAY be used with any job state or states
for which the reason makes sense.  Furthermore, when implemented, the
Printer MUST return these values when the reason applies and MUST NOT
return them when the reason no longer applies whether the value of the
Job's "job-state" attribute changed or not.  When the Job does not have
any reasons for being in its current state, the value of the Job's "job-
state-reasons" attribute MUST be 'none'.

Note: While values cannot be added to the 'job-state' attribute without
impacting deployed clients that take actions upon receiving "job-state"
values, it is the intent that additional "job-state-reasons" values can
be defined and registered without impacting such deployed clients.  In
other words, the "job-state-reasons" attribute is intended to be
extensible.

The following standard keyword values are defined.  For ease of
understanding, the values are presented in the order in which the
reasons are likely to occur (if implemented), starting with the 'job-
incoming' value:

  'none':  There are no reasons for the job's current state.
  'job-incoming':  The Create-Job operation has been accepted by the
     Printer, but the Printer is expecting additional Send-Document
     and/or Send-URI operations and/or is accessing/accepting document
     data.
  'submission-interrupted':  The job was not completely submitted for
     some unforeseen reason, such as: (1) the Printer has crashed before

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     the job was closed by the client, (2) the Printer or the document
     transfer method has crashed in some non-recoverable way before the
     document data was entirely transferred to the Printer, (3) the
     client crashed or failed to close the job before the time-out
     period.  See section 4.4.28.
  'job-outgoing':  The Printer is transmitting the job to the output
     device.
  'job-hold-until-specified':  The value of the job's "job-hold-until"
     attribute was specified with a time period that is still in the
     future.  The job MUST NOT be a candidate for processing until this
     reason is removed and there are no other reasons to hold the job.
  'resources-are-not-ready':  At least one of the resources needed by
     the job, such as media, fonts, resource objects, etc., is not ready
     on any of the physical printer's for which the job is a candidate.
     This condition MAY be detected when the job is accepted, or
     subsequently while the job is pending or processing, depending on
     implementation.  The job may remain in its current state or be
     moved to the 'pending-held' state, depending on implementation
     and/or job scheduling policy.
  'printer-stopped-partly':  The value of the Printer's "printer-state-
     reasons" attribute contains the value 'stopped-partly'.
  'printer-stopped':  The value of the Printer's "printer-state"
     attribute is 'stopped'.
  'job-interpreting': Job is in the 'processing' state, but more
     specifically, the Printer is interpreting the document data.
  'job-queued': Job is in the 'processing' state, but more
     specifically, the Printer has queued the document data.
  'job-transforming': Job is in the 'processing' state, but more
     specifically, the Printer is interpreting document data and
     producing another electronic representation.
  'job-printing':  The output device is marking media. This value is
     useful for Printers which spend a great deal of time processing (1)
     when no marking is happening and then want to show that marking is
     now happening or (2) when the job is in the process of being
     canceled or aborted while the job remains in the 'processing'
     state, but the marking has not yet stopped so that impression or
     sheet counts are still increasing for the job.
  'job-canceled-by-user':  The job was canceled by the owner of the job
     using the Cancel-Job request, i.e., by a user whose authenticated
     identity is the same as the value of the originating user that
     created the Job object, or by some other authorized end-user, such
     as a member of the job owner's security group.
  'job-canceled-by-operator':  The job was canceled by the operator
     using the Cancel-Job request, i.e., by a user who has been
     authenticated as having operator privileges (whether local or
     remote).  If the security policy is to allow anyone to cancel
     anyone's job, then this value may be used when the job is canceled
     by other than the owner of the job.  For such a security policy, in
     effect, everyone is an operator as far as canceling jobs with IPP
     is concerned.
  'job-canceled-at-device':  The job was canceled by an unidentified
     local user, i.e., a user at a console at the device.
  'aborted-by-system':  The job (1) is in the process of being aborted,
     (2) has been aborted by the system and placed in the 'aborted'

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     state, or (3) has been aborted by the system and placed in the
     'pending-held' state, so that a user or operator can manually try
     the job again.
  'processing-to-stop-point':  The requester has issued a Cancel-job
     operation or the Printer object has aborted the job, but is still
     performing some actions on the job until a specified stop point
     occurs or job termination/cleanup is completed.


     This reason is recommended to be used in conjunction with the
     'processing' job state to indicate that the Printer object is still
     performing some actions on the job while the job remains in the
     'processing' state.  After all the job's job description attributes
     have stopped incrementing, the Printer object moves the job from
     the 'processing' state to the 'canceled' or 'aborted' job states.


  'service-off-line':  The Printer is off-line and accepting no jobs.
     All 'pending' jobs are put into the 'pending-held' state.  This
     situation could be true if the service's or document transform's
     input is impaired or broken.
  'job-completed-successfully':  The job completed successfully.
  'job-completed-with-warnings':  The job completed with warnings.
  'job-completed-with-errors':  The job completed with errors (and
     possibly warnings too).
  'job-restartable' - This job is retained (see section 4.3.7.1) and is
     currently able to be restarted using the Restart-Job operation (see
     section 3.3.7).  If 'job-restartable' is a value of the job's 'job-
     state-reasons' attribute, then the IPP object MUST accept a
     Restart-Job operation for that job.

4.3.9 job-state-message (text(MAX))

This attribute specifies information about the "job-state" and "job-
state-reasons" attributes in human readable text.  If the Printer object
supports this attribute, the Printer object MUST be able to generate
this message in any of the natural languages identified by the Printer's
"generated-natural-language-supported" attribute (see the "attributes-
natural-language" operation attribute specified in Section 3.1.4.1).

Note:  the value SHOULD NOT contain additional information not contained
in the values of the "job-state" and "job-states-reasons" attributes,
such as interpreter error information.  Otherwise, application programs
might attempt to parse the (localized text).  For such additional
information such as interpreter errors for application program
consumption, a new attribute with keyword values, needs to be developed
and registered.


4.3.10 number-of-documents (integer(0:MAX))

This attribute indicates the number of documents in the job, i.e., the
number of Send-Document, Send-URI, Print-Job, or Print-URI operations
that the Printer has accepted for this job, regardless of whether the
document data has reached the Printer object or not.


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Implementations supporting the OPTIONAL Create-Job/Send-Document/Send-
URI operations SHOULD support this attribute so that clients can query
the number of documents in each job.


4.3.11 output-device-assigned (name(127))

This attribute identifies the output device to which the Printer object
has assigned this job.  If an output device implements an embedded
Printer object, the Printer object NEED NOT set this attribute.  If a
print server implements a Printer object, the value MAY be empty (zero-
length string) or not returned until the Printer object assigns an
output device to the job.  This attribute is particularly useful when a
single Printer object support multiple devices (so called "fan-out").


4.3.12 time-at-creation (integer(0:MAX))

This attribute indicates the point in time at which the Job object was
created.  In order to populate this attribute, the Printer object uses
the value in its "printer-up-time" attribute at the time the Job object
is created.


4.3.13 time-at-processing (integer(0:MAX))

This attribute indicates the point in time at which the Job object began
processing.  In order to populate this attribute, the Printer object
uses the value in its "printer-up-time" attribute at the time the Job
object is moved into the 'processing' state for the first time.


4.3.14 time-at-completed (integer(0:MAX))

This attribute indicates the point in time at which the Job object
completed (or was cancelled or aborted).  In order to populate this
attribute, the Printer object uses the value in its "printer-up-time"
attribute at the time the Job object is moved into the 'completed' or
'canceled' or 'aborted' state.


4.3.15 number-of-intervening-jobs (integer(0:MAX))

This attribute indicates the number of jobs that are "ahead" of this job
in the relative chronological order of expected time to complete (i.e.,
the current scheduled order). For efficiency, it is only necessary to
calculate this value when an operation is performed that requests this
attribute.


4.3.16 job-message-from-operator (text(127))

This attribute provides a message from an operator, system administrator
or "intelligent" process to indicate to the end user the reasons for
modification or other management action taken on a job.



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4.3.17 job-k-octets (integer(0:MAX))

This attribute specifies the total size of the document(s) in K octets,
i.e., in units of 1024 octets requested to be processed in the job.  The
value MUST be rounded up, so that a job between 1 and 1024 octets MUST
be indicated as being 1, 1025 to 2048 MUST be 2, etc.

This value MUST NOT include the multiplicative factors contributed by
the number of copies specified by the "copies" attribute, independent of
whether the device can process multiple copies without making multiple
passes over the job or document data and independent of whether the
output is collated or not.  Thus the value is independent of the
implementation and indicates the size of the document(s) measured in K
octets independent of the number of copies.

This value MUST also not include the multiplicative factor due to a
copies instruction embedded in the document data.  If the document data
actually includes replications of the document data, this value will
include such replication.  In other words, this value is always the size
of the source document data, rather than a measure of the hardcopy
output to be produced.

Note: This attribute and the following two attributes ("job-impressions"
and "job-media-sheets") are not intended to be counters; they are
intended to be useful routing and scheduling information if known.  For
these three attributes, the Printer object may try to compute the value
if it is not supplied in the create request.  Even if the client does
supply a value for these three attributes in the create request, the
Printer object MAY choose to change the value if the Printer object is
able to compute a value which is more accurate than the client supplied
value.  The Printer object may be able to determine the correct value
for these three attributes either right at job submission time or at any
later point in time.


4.3.18 job-impressions (integer(0:MAX))

This attribute specifies the total size in number of impressions of the
document(s) being submitted (see the definition of impression in section
13.2.5).

As with "job-k-octets", this value MUST NOT include the multiplicative
factors contributed by the number of copies specified by the "copies"
attribute, independent of whether the device can process multiple copies
without making multiple passes over the job or document data and
independent of whether the output is collated or not.  Thus the value is
independent of the implementation and reflects the size of the
document(s) measured in impressions independent of the number of copies.

As with "job-k-octets", this value MUST also not include the
multiplicative factor due to a copies instruction embedded in the
document data.  If the document data actually includes replications of
the document data, this value will include such replication.  In other
words, this value is always the number of impressions in the source


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document data, rather than a measure of the number of impressions to be
produced by the job.

See the Note in the "job-k-octets" attribute that also applies to this
attribute.


4.3.19 job-media-sheets (integer(0:MAX))

This attribute specifies the total number of media sheets to be produced
for this job.

Unlike the "job-k-octets" and the "job-impressions" attributes, this
value MUST include the multiplicative factors contributed by the number
of copies specified by the "copies" attribute and a 'number of copies'
instruction embedded in the document data, if any.  This difference
allows the system administrator to control the lower and upper bounds of
both (1) the size of the document(s) with "job-k-octets-supported" and
"job-impressions-supported" and (2) the size of the job with "job-media-
sheets-supported".

See the Note in the "job-k-octets" attribute that also applies to this
attribute.


4.3.20 job-k-octets-processed (integer(0:MAX))

This attribute specifies the total number of octets processed in K
octets, i.e., in units of 1024 octets so far.  The value MUST be rounded
up, so that a job between 1 and 1024 octets inclusive MUST be indicated
as being 1, 1025 to 2048 inclusive MUST be 2, etc.

For implementations where multiple copies are produced by the
interpreter with only a single pass over the data, the final value MUST
be equal to the value of the "job-k-octets" attribute.  For
implementations where multiple copies are produced by the interpreter by
processing the data for each copy, the final value MUST be a multiple of
the value of the "job-k-octets" attribute.

Note: This attribute and the following two attributes ("job-impressions-
completed" and "job-sheets-completed") are intended to be counters. That
is, the value for a job that has not started processing MUST be 0.  When
the job's "job-state" is 'processing' or 'processing-stopped', this
value is intended to contain the amount of the job that has been
processed to the time at which the attributes are requested.


4.3.21 job-impressions-completed (integer(0:MAX))

This job attribute specifies the number of impressions completed for the
job so far.  For printing devices, the impressions completed includes
interpreting, marking, and stacking the output.

See the note in "job-k-octets-processed" which also applies to this
attribute.


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4.3.22 job-media-sheets-completed (integer(0:MAX))

This job attribute specifies the media-sheets completed marking and
stacking for the entire job so far whether those sheets have been
processed on one side or on both.

See the note in "job-k-octets-processed" which also applies to this
attribute.


4.3.23 attributes-charset (charset)

This REQUIRED attribute is populated using the value in the client
supplied "attributes-charset" attribute in the create request.  It
identifies the charset (coded character set and encoding method) used by
any Job attributes with attribute syntax 'text' and 'name' that were
supplied by the client in the create request.  See Section 3.1.4 for a
complete description of the "attributes-charset" operation attribute.

This attribute does not indicate the charset in which the 'text' and
'name' values are stored internally in the Job object.  The internal
charset is implementation-defined.  The IPP object MUST convert from
whatever the internal charset is to that being requested in an operation
as specified in Section 3.1.4.


4.3.24 attributes-natural-language (naturalLanguage)

This REQUIRED attribute is populated using the value in the client
supplied "attributes-natural-language" attribute in the create request.
It identifies the natural language used for any Job attributes with
attribute syntax 'text' and 'name' that were supplied by the client in
the create request.  See Section 3.1.4 for a complete description of the
"attributes-natural-language" operation attribute.  See Sections 4.1.1.2
and 4.1.2.2 for how a Natural Language Override may be supplied
explicitly for each 'text' and 'name' attribute value that differs from
the value identified by the "attributes-natural-language" attribute.


4.4 Printer Description Attributes


These attributes form the attribute group called "printer-description".
The following table summarizes these attributes, their syntax, and
whether or not they are REQUIRED for a Printer object to support.  If
they are not indicated as REQUIRED, they are OPTIONAL.  The maximum size
in octets for 'text' and 'name' attributes is indicated in
parenthesizes.

Note: How these attributes are set by an Administrator is outside the
scope of this IPP/1.1 document.






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+----------------------------+---------------------------+-----------+
|      Attribute             |     Syntax                | REQUIRED? |
+----------------------------+---------------------------+-----------+
| printer-uri-supported      | 1setOf uri                |  REQUIRED |
+----------------------------+---------------------------+-----------+
| uri-security-supported     | 1setOf type2 keyword      |  REQUIRED |
+----------------------------+---------------------------+-----------+
| printer-name               | name (127)                |  REQUIRED |
+----------------------------+---------------------------+-----------+
| printer-location           | text (127)                |           |
+----------------------------+---------------------------+-----------+
| printer-info               | text (127)                |           |
+----------------------------+---------------------------+-----------+
| printer-more-info          | uri                       |           |
+----------------------------+---------------------------+-----------+
| printer-driver-installer   | uri                       |           |
+----------------------------+---------------------------+-----------+
| printer-make-and-model     | text (127)                |           |
+----------------------------+---------------------------+-----------+
| printer-more-info-         | uri                       |           |
| manufacturer               |                           |           |
+----------------------------+---------------------------+-----------+
| printer-state              | type1 enum                |  REQUIRED |
+----------------------------+---------------------------+-----------+
| printer-state-reasons      | 1setOf type2 keyword      |           |
+----------------------------+---------------------------+-----------+
| printer-state-message      | text (MAX)                |           |
+----------------------------+---------------------------+-----------+
| operations-supported       | 1setOf type2 enum         |  REQUIRED |
+----------------------------+---------------------------+-----------+
| charset-configured         | charset                   |  REQUIRED |
+----------------------------+---------------------------+-----------+
| charset-supported          | 1setOf charset            |  REQUIRED |
+----------------------------+---------------------------+-----------+
| natural-language-configured| naturalLanguage           |  REQUIRED |
+----------------------------+---------------------------+-----------+
| generated-natural-language-| 1setOf naturalLanguage    |  REQUIRED |
| supported                  |                           |           |
+----------------------------+---------------------------+-----------+
| document-format-default    | mimeMediaType             |  REQUIRED |
+----------------------------+---------------------------+-----------+
| document-format-supported  | 1setOf mimeMediaType      |  REQUIRED |
+----------------------------+---------------------------+-----------+
| printer-is-accepting-jobs  | boolean                   |  REQUIRED |
+----------------------------+---------------------------+-----------+
| queued-job-count           | integer (0:MAX)           |RECOMMENDED|
+----------------------------+---------------------------+-----------+
| printer-message-from-      | text (127)                |           |
| operator                   |                           |           |
+----------------------------+---------------------------+-----------+
| color-supported            | boolean                   |           |
+----------------------------+---------------------------+-----------+
| reference-uri-schemes-     | 1setOf uriScheme          |           |
|   supported                |                           |           |

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+----------------------------+---------------------------+-----------+
| pdl-override-supported     | type2 keyword             |  REQUIRED |
+----------------------------+---------------------------+-----------+
| printer-up-time            | integer (1:MAX)           |  REQUIRED |
+----------------------------+---------------------------+-----------+
| printer-current-time       | dateTime                  |           |
+----------------------------+---------------------------+-----------+
| multiple-operation-time-out| integer (1:MAX)           |           |
+----------------------------+---------------------------+-----------+
| compression-supported      | 1setOf type3 keyword      |           |
+----------------------------+---------------------------+-----------+
| job-k-octets-supported     | rangeOfInteger (0:MAX)    |           |
+----------------------------+---------------------------+-----------+
| job-impressions-supported  | rangeOfInteger (0:MAX)    |           |
+----------------------------+---------------------------+-----------+
| job-media-sheets-supported | rangeOfInteger (0:MAX)    |           |
+----------------------------+---------------------------+-----------+
| pages-per-minute           | integer(0:MAX)            |           |
+----------------------------+---------------------------+-----------+
| pages-per-minute-color     | integer(0:MAX)            |           |
+----------------------------+---------------------------+-----------+


4.4.1 printer-uri-supported (1setOf uri)

This REQUIRED Printer attribute contains at least one URI for the
Printer object.  It OPTIONALLY contains more than one URI for the
Printer object.    An administrator determines a Printer object's URI(s)
and configures this attribute to contain those URIs by some means
outside the scope of this IPP/1.1 document.  The precise format of this
URI is implementation dependent and depends on the protocol.  See the
next section for a description "uri-security-supported" which is the
REQUIRED companion attribute to this "printer-uri-supported" attribute.
See section 2.4 on Printer object identity and section 8.2 on security
and URIs for more information.


4.4.2 uri-security-supported (1setOf type2 keyword)

This REQUIRED Printer attribute MUST have the same cardinality (contain
the same number of values) as the "printer-uri-supported" attribute.
This attribute identifies the security mechanisms used for each URI
listed in the "printer-uri-supported" attribute.  The "i th" value in
"uri-security-supported" corresponds to the "i th" value in "printer-
uri-supported" and it describes the security mechanisms used for
accessing the Printer object via that URI. The following standard values
are defined:

  'none': There are no secure communication channel protocols in use
     for the given URI.
  'ssl3': SSL3 [SSL] is the secure communications channel protocol in
     use for the given URI. For use in IPP/1.0.
  'tls':  TLS [RFC2246] is the secure communications channel protocol
     in use for the given URI.  For use in IPP/1.1.


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Consider the following example.  For a single Printer object, an
administrator configures the "printer-uri-supported" and "uri-security-
supported" attributes as follows:

  "printer-uri-supported": 'xxx://acme.com/open-use-printer',
     'xxx://acme.com/restricted-use-printer', 'xxx://acme.com/private-
     printer'
  "uri-security-supported": 'none', 'none', 'tls'


Note:  'xxx'  is not a valid scheme.  See the IPP/1.1 "Transport and
Encoding" specification [ipp-pro] for the actual URI schemes to be used
in object target attributes.

In this case, one Printer object has three URIs.

  - For the first URI, 'xxx://acme.com/open-use-printer', the value
     'none' in "uri-security-supported" indicates that there is no
     secure channel protocol configured to run under HTTP.  The name
     implies that there is no Basic or Digest authentication being used,
     but it is up to the client to determine that while using HTTP
     underneath the IPP application protocol.
  - For the second URI, 'xxx://acme.com/restricted-use-printer', the
     value 'none' in "uri-security-supported" indicates that there is no
     secure channel protocol configured to run under HTTP.  In this
     case, although the name does imply that there is some sort of Basic
     or Digest authentication being used within HTTP, it is up to the
     client to determine that while using HTTP and by processing any
     '401 Unauthorized' HTTP error messages.
  - For the third URI, 'xxx://acme.com/private-printer', the value
     'tls' in "uri-security-supported" indicates that TLS is being used
     to secure the channel.  The client SHOULD be prepared to use TLS
     framing to negotiate an acceptable ciphersuite to use while
     communicating with the Printer object.  In this case, the name
     implies the use of a secure communications channel, but the fact is
     made explicit by the presence of the 'tls' value in "uri-security-
     supported".  The client does not need to resort to understanding
     which security it must use by following naming conventions or by
     parsing the URI to determine which security mechanisms are implied.


It is expected that many IPP Printer objects will be configured to
support only one channel (either configured to use TLS access or not),
and will therefore only ever have one URI listed in the "printer-uri-
supported" attribute.  No matter the configuration of the Printer object
(whether it has only one URI or more than one URI), a client MUST supply
only one URI in the target "printer-uri" operation attribute.


4.4.3 printer-name (name(127))

This REQUIRED Printer attribute contains the name of the Printer object.
It is a name that is more end-user friendly than a URI. An administrator
determines a printer's name and sets this attribute to that name. This
name may be the last part of the printer's URI or it may be unrelated.



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In non-US-English locales, a name may contain characters that are not
allowed in a URI.


4.4.4 printer-location (text(127))

This Printer attribute identifies the location of the device. This could
include things like: "in Room 123A, second floor of building XYZ".


4.4.5 printer-info (text(127))

This Printer attribute identifies the descriptive information about this
Printer object.  This could include things like: "This printer can be
used for printing color transparencies for HR presentations", or "Out of
courtesy for others, please print only small (1-5 page) jobs at this
printer", or even "This printer is going away on July 1, 1997, please
find a new printer".


4.4.6 printer-more-info (uri)

This Printer attribute contains a URI used to obtain more information
about this specific Printer object.  For example, this could be an HTTP
type URI referencing an HTML page accessible to a Web Browser.  The
information obtained from this URI is intended for end user consumption.
Features outside the scope of IPP can be accessed from this URI.  The
information is intended to be specific to this printer instance and site
specific services (e.g. job pricing, services offered, end user
assistance). The device manufacturer may initially populate this
attribute.


4.4.7 printer-driver-installer (uri)

This Printer attribute contains a URI to use to locate the driver
installer for this Printer object.   This attribute is intended for
consumption by automata.  The mechanics of print driver installation is
outside the scope of this IPP/1.1 document.  The device manufacturer may
initially populate this attribute.


4.4.8 printer-make-and-model (text(127))

This Printer attribute identifies the make and model of the device.  The
device manufacturer may initially populate this attribute.


4.4.9 printer-more-info-manufacturer (uri)

This Printer attribute contains a URI used to obtain more information
about this type of device.  The information obtained from this URI is
intended for end user consumption.  Features outside the scope of IPP
can be accessed from this URI (e.g., latest firmware, upgrades, print
drivers, optional features available, details on color support).  The
information is intended to be germane to this printer without regard to


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site specific modifications or services. The device manufacturer may
initially populate this attribute.


4.4.10 printer-state (type1 enum)

This REQUIRED Printer attribute identifies the current state of the
device.  The "printer-state reasons" attribute augments the "printer-
state" attribute to give more detailed information about the Printer in
the given printer state.

A Printer object need only update this attribute before responding to an
operation which requests the attribute; the Printer object NEED NOT
update this attribute continually, since asynchronous event notification
is not part of IPP/1.1.  A Printer NEED NOT implement all values if they
are not applicable to a given implementation.

The following standard enum values are defined:

  Value  Symbolic Name and Description

  '3'    'idle':  If a Printer receives a job (whose required resources
               are ready) while in this state, such a job MUST transit
               into the 'processing' state immediately.  If the
               "printer-state-reasons" attribute contains any reasons,
               they MUST be reasons that would not prevent a job from
               transiting into the 'processing' state immediately, e.g.,
               'toner-low'. Note: if a Printer controls more than one
               output device, the above definition implies that a
               Printer is 'idle' if at least one output device is idle.

  '4'    'processing':  If a Printer receives a job (whose required
               resources are ready) while in this state, such a job MUST
               transit into the 'pending' state immediately. Such a job
               MUST transit into the 'processing' state only after jobs
               ahead of it complete.  If the "printer-state-reasons"
               attribute contains any reasons, they MUST be reasons that
               do not prevent the current job from printing, e.g.
               'toner-low'.  Note: if a Printer controls more than one
               output device, the above definition implies that a
               Printer is 'processing' if at least one output device is
               processing, and none is idle.

  '5'    'stopped':  If a Printer receives a job (whose required
               resources are ready) while in this state, such a job MUST
               transit into the 'pending' state immediately. Such a job
               MUST transit into the 'processing' state only after some
               human fixes the problem that stopped the printer and
               after jobs ahead of it complete processing.  If
               supported, the "printer-state-reasons" attribute MUST
               contain at least one reason, e.g. 'media-jam', which
               prevents it from either processing the current job or
               transitioning a 'pending' job to the 'processing' state.



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               Note: if a Printer controls more than one output device,
               the above definition implies that a Printer is 'stopped'
               only if all output devices are stopped.  Also, it is
               tempting to define 'stopped' as when a sufficient number
               of output devices are stopped and leave it to an
               implementation to define the sufficient number.  But such
               a rule complicates the definition of 'stopped' and
               'processing'. For example, with this alternate definition
               of 'stopped', a job can move from 'pending' to
               'processing' without human intervention, even though the
               Printer is stopped.


4.4.11 printer-state-reasons (1setOf type2 keyword)

This Printer attribute supplies additional detail about the device's
state.

Each keyword value MAY have a suffix to indicate its level of severity.
The three levels are: report (least severe), warning, and error (most
severe).

  - '-report':  This suffix indicates that the reason is a "report". An
     implementation may choose to omit some or all reports. Some reports
     specify finer granularity about the printer state; others serve as
     a precursor to a warning. A report MUST contain nothing that could
     affect the printed output.
  - '-warning': This suffix indicates that the reason is a "warning".
     An implementation may choose to omit some or all warnings. Warnings
     serve as a precursor to an error. A warning MUST contain nothing
     that prevents a job from completing, though in some cases the
     output may be of lower quality.
  - '-error': This suffix indicates that the reason is an "error".  An
     implementation MUST include all errors. If this attribute contains
     one or more errors, printer MUST be in the stopped state.


If the implementation does not add any one of the three suffixes, all
parties MUST assume that the reason is an "error".

If a Printer object controls more than one output device, each value of
this attribute MAY apply to one or more of the output devices.  An error
on one output device that does not stop the Printer object as a whole
MAY appear as a warning in the Printer's "printer-state-reasons
attribute".  If the "printer-state" for such a Printer has a value of
'stopped', then there MUST be an error reason among the values in the
"printer-state-reasons" attribute.

The following standard keyword values are defined:

  'other': The device has detected an error other than one listed in
     this document.
  'none': There are not reasons. This state reason is semantically
     equivalent to "printer-state-reasons" without any value.



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  'media-needed': A tray has run out of media.
  'media-jam': The device has a media jam.
  'moving-to-paused':  Someone has paused the Printer object using the
     Pause-Printer operation (see section 3.2.7) or other means, but the
     device(s) are taking an appreciable time to stop.  Later, when all
     output has stopped, the "printer-state" becomes 'stopped', and the
     'paused' value replaces the 'moving-to-paused' value in the
     "printer-state-reasons" attribute.
  'paused': Someone has paused the Printer object using the Pause-
     Printer operation (see section 3.2.7) or other means and the
     Printer object's "printer-state" is 'stopped'.  In this state, a
     Printer MUST NOT produce printed output, but it MUST perform other
     operations requested by a client.  If a Printer had been printing a
     job when the Printer was paused, the Printer MUST resume printing
     that job when the Printer is no longer paused and leave no evidence
     in the printed output of such a pause.
  'shutdown': Someone has removed a Printer object from service, and
     the device may be powered down or physically removed.  In this
     state, a Printer object MUST NOT produce printed output, and unless
     the Printer object is realized by a print server that is still
     active, the Printer object MUST perform no other operations
     requested by a client, including returning this value. If a Printer
     object had been printing a job when it was shutdown, the Printer
     NEED NOT resume printing that job when the Printer is no longer
     shutdown. If the Printer resumes printing such a job, it may leave
     evidence in the printed output of such a shutdown, e.g. the part
     printed before the shutdown may be printed a second time after the
     shutdown.
  'connecting-to-device': The Printer object has scheduled a job on the
     output device and is in the process of connecting to a shared
     network output device (and might not be able to actually start
     printing the job for an arbitrarily long time depending on the
     usage of the output device by other servers on the network).
  'timed-out': The server was able to connect to the output device (or
     is always connected), but was unable to get a response from the
     output device.
  'stopping': The Printer object is in the process of stopping the
     device and will be stopped in a while. When the device is stopped,
     the Printer object will change the Printer object's state to
     'stopped'.  The 'stopping-warning' reason is never an error, even
     for a Printer with a single output device.  When an output-device
     ceases accepting jobs, the Printer will have this reason while the
     output device completes printing.
  'stopped-partly': When a Printer object controls more than one output
     device, this reason indicates that one or more output devices are
     stopped.  If the reason is a report, fewer than half of the output
     devices are stopped.  If the reason is a warning, fewer than all of
     the output devices are stopped.
  'toner-low': The device is low on toner.
  'toner-empty':  The device is out of toner.
  'spool-area-full': The limit of persistent storage allocated for
     spooling has been reached.
  'cover-open': One or more covers on the device are open.


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  'interlock-open': One or more interlock devices on the printer are
     unlocked.
  'door-open': One or more doors on the device are open.
  'input-tray-missing': One or more input trays are not in the device.
  'media-low': At least one input tray is low on media.
  'media-empty': At least one input tray is empty.
  'output-tray-missing': One or more output trays are not in the device
  'output-area-almost-full': One or more output area is almost full
     (e.g. tray, stacker, collator).
  'output-area-full': One or more output area is full. (e.g. tray,
     stacker, collator)
  'marker-supply-low': The device is low on at least one marker supply.
     (e.g. toner, ink, ribbon)
  'marker-supply-empty: The device is out of at least one marker
     supply. (e.g. toner, ink, ribbon)
  'marker-waste-almost-full': The device marker supply waste receptacle
     is almost full.
  'marker-waste-full': The device marker supply waste receptacle is
     full.
  'fuser-over-temp': The fuser temperature is above normal.
  'fuser-under-temp': The fuser temperature is below normal.
  'opc-near-eol': The optical photo conductor is near end of life.
  'opc-life-over': The optical photo conductor is no longer
     functioning.
  'developer-low': The device is low on developer.
  'developer-empty: The device is out of developer.
  'interpreter-resource-unavailable': An interpreter resource is
     unavailable (i.e. font, form)



4.4.12 printer-state-message (text(MAX))

This Printer attribute specifies the additional information about the
printer state and printer state reasons in human readable text.  If the
Printer object supports this attribute, the Printer object MUST be able
to generate this message in any of the natural languages identified by
the Printer's "generated-natural-language-supported" attribute (see the
"attributes-natural-language" operation attribute specified in Section
3.1.4.1).


4.4.13 operations-supported (1setOf type2 enum)

This REQUIRED Printer attribute specifies the set of supported
operations for this Printer object and contained Job objects.

Note:  This attribute is encoded as any other enum attribute syntax
according to [IPP-PRO] as 32-bits.  However, all 32-bit enum values for
this attribute MUST NOT exceed 0x00008FFF, since these same values are
also passed in two octets in the "operation-id" parameter (see section
3.1.1) in each Protocol request with the two high order octets omitted
in order to indicate the operation being performed [IPP-PRO].



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The following standard enum and "operation-id" (see section 3.1.2)
values are defined:

  Value               Operation Name
  -----------------   -------------------------------------

  0x0000              reserved, not used
  0x0001              reserved, not used
  0x0002              Print-Job
  0x0003              Print-URI
  0x0004              Validate-Job
  0x0005              Create-Job
  0x0006              Send-Document
  0x0007              Send-URI
  0x0008              Cancel-Job
  0x0009              Get-Job-Attributes
  0x000A              Get-Jobs
  0x000B              Get-Printer-Attributes
  0x000C              Hold-Job
  0x000D              Release-Job
  0x000E              Restart-Job
  0x000F              reserved for a future operation
  0x0010              Pause-Printer
  0x0011              Resume-Printer
  0x0012              Purge-Jobs
  0x00013-0x3FFF      reserved for future operations
  0x4000-0x8FFF       reserved for private extensions


This allows for certain vendors to implement private extensions that are
guaranteed to not conflict with future registered extensions.  However,
there is no guarantee that two or more private extensions will not
conflict.


4.4.14 charset-configured (charset)

This REQUIRED Printer attribute identifies the charset that the Printer
object has been configured to represent 'text' and 'name' Printer
attributes that are set by the operator, system administrator, or
manufacturer, i.e., for "printer-name" (name), "printer-location"
(text), "printer-info" (text), and "printer-make-and-model" (text).
Therefore, the value of the Printer object's "charset-configured"
attribute MUST also be among the values of the Printer object's
"charset-supported" attribute.


4.4.15 charset-supported (1setOf charset)

This REQUIRED Printer attribute identifies the set of charsets that the
Printer and contained Job objects support in attributes with attribute
syntax 'text' and 'name'. At least the value 'utf-8' MUST be present,
since IPP objects MUST support the UTF-8 [RFC2279] charset.  If a
Printer object supports a charset, it means that for all attributes of
syntax 'text' and 'name' the IPP object MUST (1) accept the charset in
requests and return the charset in responses as needed.

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If more charsets than UTF-8 are supported, the IPP object MUST perform
charset conversion between the charsets as described in Section 3.2.1.2.


4.4.16 natural-language-configured (naturalLanguage)

This REQUIRED Printer attribute identifies the natural language that the
Printer object has been configured to represent 'text' and 'name'
Printer attributes that are set by the operator, system administrator,
or manufacturer, i.e., for "printer-name" (name), "printer-location"
(text), "printer-info" (text), and "printer-make-and-model" (text).
When returning these Printer attributes, the Printer object MAY return
them in the configured natural language specified by this attribute,
instead of the natural language requested by the client in the
"attributes-natural-language" operation attribute.  See Section 3.1.4.1
for the specification of the OPTIONAL multiple natural language support.
Therefore, the value of the Printer object's "natural-language-
configured" attribute MUST also be among the values of the Printer
object's "generated-natural-language-supported" attribute.


4.4.17 generated-natural-language-supported (1setOf naturalLanguage)

This REQUIRED Printer attribute identifies the natural language(s) that
the Printer object and contained Job objects support in attributes with
attribute syntax 'text' and 'name'.  The natural language(s) supported
depends on implementation and/or configuration.  Unlike charsets, IPP
objects MUST accept requests with any natural language or any Natural
Language Override whether the natural language is supported or not.

If a Printer object supports a natural language, it means that for any
of the attributes for which the Printer or Job object generates
messages, i.e., for the "job-state-message" and "printer-state-message"
attributes and Operation Messages (see Section 3.1.5) in operation
responses, the Printer and Job objects MUST be able to generate messages
in any of the Printer's supported natural languages.  See section 3.1.4
for the specification of 'text' and 'name' attributes in operation
requests and responses.

Note: A Printer object that supports multiple natural languages, often
has separate catalogs of messages, one for each natural language
supported.


4.4.18 document-format-default (mimeMediaType)

This REQUIRED Printer attribute identifies the document format that the
Printer object has been configured to assume if the client does not
supply a "document-format" operation attribute in any of the operation
requests that supply document data.  The standard values for this
attribute are Internet Media types (sometimes called MIME types).  For
further details see the description of the 'mimeMediaType' attribute
syntax in Section 4.1.9.




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4.4.19 document-format-supported (1setOf mimeMediaType)

This REQUIRED Printer attribute identifies the set of document formats
that the Printer object and contained Job objects can support. For
further details see the description of the 'mimeMediaType' attribute
syntax in Section 4.1.9.


4.4.20 printer-is-accepting-jobs (boolean)

This REQUIRED Printer attribute indicates whether the printer is
currently able to accept jobs, i.e., is accepting Print-Job, Print-URI,
and Create-Job requests.  If the value is 'true', the printer is
accepting jobs.  If the value is 'false', the Printer object is
currently rejecting any jobs submitted to it.  In this case, the Printer
object returns the 'server-error-not-accepting-jobs' status code.

Note: This value is independent of the "printer-state" and "printer-
state-reasons" attributes because its value does not affect the current
job; rather it affects future jobs.  This attribute may cause the
Printer to reject jobs when the "printer-state" is 'idle' or it may
cause the Printer object to accepts jobs when the "printer-state" is
'stopped'.


4.4.21 queued-job-count (integer(0:MAX))

This RECOMMENDED Printer attribute contains a count of the number of
jobs that are either 'pending', 'processing', 'pending-held', or
'processing-stopped' and is set by the Printer object.


4.4.22 printer-message-from-operator (text(127))

This Printer attribute provides a message from an operator, system
administrator or "intelligent" process to indicate to the end user
information or status of the printer, such as why it is unavailable or
when it is expected to be available.


4.4.23 color-supported (boolean)

This Printer attribute identifies whether the device is capable of any
type of color printing at all, including highlight color.  All document
instructions having to do with color are embedded within the document
PDL (none are external IPP attributes in IPP/1.1).

Note:  end-users are able to determine the nature and details of the
color support by querying the "printer-more-info-manufacturer" Printer
attribute.


4.4.24 reference-uri-schemes-supported (1setOf uriScheme)

This Printer attribute specifies which URI schemes are supported for use
in the "document-uri" operation attribute of the Print-URI or Send-URI


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operation.  If a Printer object supports these optional operations, it
MUST support the "reference-uri-schemes-supported" Printer attribute
with at least the following schemed URI value:

  'ftp':  The Printer object will use an FTP 'get' operation as defined
     in RFC 2228 [RFC2228] using FTP URLs as defined by [RFC2396]
     and[RFC2316].


The Printer object MAY OPTIONALLY support other URI schemes (see section
4.1.6).


4.4.25 pdl-override-supported (type2 keyword)

This REQUIRED Printer attribute expresses the ability for a particular
Printer implementation to either attempt to override document data
instructions with IPP attributes or not.

This attribute takes on the following values:

  - 'attempted': This value indicates that the Printer object attempts
     to make the IPP attribute values take precedence over embedded
     instructions in the document data, however there is no guarantee.
  - 'not-attempted': This value indicates that the Printer object makes
     no attempt to make the IPP attribute values take precedence over
     embedded instructions in the document data.


Section 16 contains a full description of how this attribute interacts
with and affects other IPP attributes, especially the "ipp-attribute-
fidelity" attribute.


4.4.26 printer-up-time (integer(1:MAX))

This REQUIRED Printer attribute indicates the amount of time (in
seconds) that this instance of this Printer implementation has been up
and running.  This value is used to populate the Job attributes "time-
at-creation", "time-at-processing", and "time-at-completed".  These time
values are all measured in seconds and all have meaning only relative to
this attribute, "printer-up-time".  The value is a monotonically
increasing value starting from 1 when the Printer object is started-up
(initialized, booted, etc.).

If the Printer object goes down at some value 'n', and comes back up,
the implementation MAY:

  1. Know how long it has been down, and resume at some value greater
     than 'n', or
  2. Restart from 1.


In the first case, the Printer SHOULD not tweak any existing related Job
attributes ("time-at-creation", "time-at-processing", and "time-at-
completed").  In the second case, the Printer object SHOULD reset those
attributes to 0.  If a client queries a time-related Job attribute and


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finds the value to be 0, the client MUST assume that the Job was
submitted in some life other than the Printer's current life.


4.4.27 printer-current-time (dateTime)

This Printer attribute indicates the current absolute wall-clock time.
If an implementation supports this attribute, then a client could
calculate the absolute wall-clock time each Job's "time-at-creation",
"time-at-processing", and "time-at-completed" attributes by using both
"printer-up-time" and this attribute, "printer-current-time".  If an
implementation does not support this attribute, a client can only
calculate the relative time of certain events based on the REQUIRED
"printer-up-time" attribute.


4.4.28 multiple-operation-time-out (integer(1:MAX))

This Printer attributes identifies the minimum time (in seconds) that
the Printer object waits for additional Send-Document or Send-URI
operations to follow a still-open multi-document Job object before
taking  any recovery actions, such as the ones indicated in section
3.3.1.  If the Printer object supports the Create-Job operation (see
section 3.2.4), it MUST support this attribute.

It is RECOMMENDED that vendors supply a value for this attribute that is
between 60 and 240 seconds.  An implementation MAY allow a system
administrator to set this attribute (by means outside this IPP/1.1
document).  If so, the system administrator MAY be able to set values
outside this range.


4.4.29 compression-supported (1setOf type3 keyword)

This Printer attribute identifies the set of supported compression
algorithms for document data.  Compression only applies to the document
data; compression does not apply to the encoding of the IPP operation
itself.  The supported values are used to validate the client supplied
"compression" operation attributes in Print-Job, Send-Document, and
Send-URI requests.

Standard values are :

  'none': no compression is used.
  'deflate':  ZIP public domain inflate/deflate) compression technology
  'gzip' GNU zip compression technology described in RFC 1952
     [RFC1952].
  'compress': UNIX compression technology


4.4.30 job-k-octets-supported (rangeOfInteger(0:MAX))

This Printer attribute specifies the upper and lower bounds of total
sizes of jobs in K octets, i.e., in units of 1024 octets. The supported
values are used to validate the client supplied "job-k-octets" operation


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attributes in create requests.  The corresponding job description
attribute "job-k-octets" is defined in section 4.3.17.


4.4.31 job-impressions-supported (rangeOfInteger(0:MAX))

This Printer attribute specifies the upper and lower bounds for the
number of impressions per job. The supported values are used to validate
the client supplied "job-impressions" operation attributes in create
requests.  The corresponding job description attribute "job-impressions"
is defined in section 4.3.18.


4.4.32 job-media-sheets-supported (rangeOfInteger(0:MAX))

This Printer attribute specifies the upper and lower bounds for the
number of media sheets per job. The supported values are used to
validate the client supplied "job-media-sheets" operation attributes in
create requests.  The corresponding Job attribute "job-media-sheets" is
defined in section 4.3.19.


4.4.33 pages-per-minute (integer(0:MAX))

This Printer attributes specifies the nominal number of pages per minute
to the nearest whole number which may be generated by this printer
(e.g., simplex, black-and-white).  This attribute is informative, not a
service guarantee.  Generally, it is the value used in the marketing
literature to describe the device.

A value of 0 indicates a device that takes more than two minutes to
process a page.


4.4.34 pages-per-minute-color (integer(0:MAX))

This Printer attributes specifies the nominal number of pages per minute
to the nearest whole number which may be generated by this printer when
printing color (e.g., simplex, color).  For purposes of this attribute,
"color" means the same as for the "color-supported" attribute, namely,
the device is capable of any type of color printing at all, including
highlight color.  This attribute is informative, not a service
guarantee.  Generally, it is the value used in the marketing literature
to describe the color capabilities of this device.

A value of 0 indicates a device that takes more than two minutes to
process a page.

Note:  If a color device has several color modes, it MAY use the pages-
per-minute value for this attribute that corresponds to the mode that
produces the highest number.

Black and white only printers MUST NOT support this attribute.  If this
attribute is present, then the "color-supported" Printer description
attribute MUST be present and have a 'true' value.


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Note:  The values of these two attributes returned by the Get-Printer-
Attributes operation MAY be affected by the "document-format" attribute
supplied by the client in the Get-Printer-Attributes request.  In other
words, the implementation MAY have different speeds depending on the
document format being processed.  See section 3.2.5.1 Get-Printer-
Attributes.



5. Conformance


This section describes conformance issues and requirements. This
document introduces model entities such as objects, operations,
attributes, attribute syntaxes, and attribute values.  These conformance
sections describe the conformance requirements which apply to these
model entities.


5.1 Client Conformance Requirements


A conforming client MUST support all REQUIRED operations as defined in
this document.  For each attribute included in an operation request, a
conforming client MUST supply a value whose type and value syntax
conforms to the requirements of the Model document as specified in
Sections 3 and 3.3.5.  A conforming client MAY supply any registered
extensions and/or private extensions in an operation request, as long as
they meet the requirements in Section 6.

Otherwise, there are no conformance requirements placed on the user
interfaces provided by IPP clients or their applications.  For example,
one application might not allow an end user to submit multiple documents
per job, while another does.  One application might first query a
Printer object in order to supply a graphical user interface (GUI)
dialogue box with supported and default values whereas a different
implementation might not.

When sending a request, an IPP client NEED NOT supply any attributes
that are indicated as OPTIONALLY supplied by the client.

A client MUST be able to accept any of the attribute syntaxes defined in
Section 4.1, including their full range, that may be returned to it in a
response from a Printer object.  In particular for each attribute that
the client supports whose attribute syntax is 'text', the client MUST
accept and process both the 'textWithoutLanguage' and 'textWithLanguage'
forms.  Similarly, for each attribute that the client supports whose
attribute syntax is 'name', the client MUST accept and process both the
'nameWithoutLanguage' and 'nameWithLanguage' forms.  For presentation
purposes, truncation of long attribute values is not recommended.  A
recommended approach would be for the client implementation to allow the
user to scroll through long attribute values.

A query response may contain attribute groups, attributes, and values
that the client does not expect.  Therefore, a client implementation
MUST gracefully handle such responses and not refuse to inter-operate

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with a conforming Printer that is returning extended registered or
private attributes and/or attribute values that conform to Section 6.
Clients may choose to ignore any parameters, attributes, or values that
they do not understand.


5.2 IPP Object Conformance Requirements


This section specifies the conformance requirements for conforming
implementations with respect to objects, operations, and attributes.


5.2.1 Objects

Conforming implementations MUST implement all of the model objects as
defined in this specification in the indicated sections:

  Section 2.1 - Printer Object
  Section 2.2 - Job Object


5.2.2 Operations

Conforming IPP object implementations MUST implement all of the REQUIRED
model operations, including REQUIRED responses, as defined in this
specification in the indicated sections:

  For a Printer object:
     Print-Job (section 3.2.1)          REQUIRED
     Print-URI (section 3.2.2)          OPTIONAL
     Validate-Job (section 3.2.3)       REQUIRED
     Create-Job (section 3.2.4)         OPTIONAL
     Get-Printer-Attributes (section 3.2.5)  REQUIRED
     Get-Jobs (section 3.2.6)           REQUIRED
     Pause-Printer (section 3.2.7)      OPTIONAL
     Resume-Printer (section 3.2.8)     OPTIONAL
     Purge-Jobs (section 3.2.9)         OPTIONAL

  For a Job object:
     Send-Document (section 3.3.1)      OPTIONAL
     Send-URI (section 3.3.2)           OPTIONAL
     Cancel-Job (section 3.3.3)         REQUIRED
     Get-Job-Attributes (section 3.3.4) REQUIRED
     Hold-Job (section 3.3.5)           OPTIONAL
     Release-Job (section 3.3.6)        OPTIONAL
     Restart-Job (section 3.3.7)        OPTIONAL


Conforming IPP objects MUST support all REQUIRED operation attributes
and all values of such attributes if so indicated in the description.
Conforming IPP objects MUST ignore all unsupported or unknown operation
attributes or operation attribute groups received in a request, but MUST
reject a request that contains a supported operation attribute that
contains an unsupported value.



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The following section on object attributes specifies the support
required for object attributes.


5.2.3 IPP Object Attributes

Conforming IPP objects MUST support all of the REQUIRED object
attributes, as defined in this specification in the indicated sections.

If an object supports an attribute, it MUST support only those values
specified in this document or through the extension mechanism described
in section 5.2.4. It MAY support any non-empty subset of these values.
That is, it MUST support at least one of the specified values and at
most all of them.


5.2.4 Versions

Clients MUST support version 1.1 and MAY also support version 1.0.  IPP
objects MUST support both version 1.0 and 1.1.  See section 3.1.7.


5.2.5 Extensions

A conforming IPP object MAY support registered extensions and private
extensions, as long as they meet the requirements specified in Section
6.

For each attribute included in an operation response, a conforming IPP
object MUST return a value whose type and value syntax conforms to the
requirement of the Model document as specified in Sections 3 and 3.3.5.


5.2.6 Attribute Syntaxes

An IPP object MUST be able to accept any of the attribute syntaxes
defined in Section 4.1, including their full range, in any operation in
which a client may supply attributes or the system administrator may
configure attributes (by means outside the scope of this IPP/1.1
document).  In particular for each attribute that the IPP object
supports whose attribute syntax is 'text', the IPP object MUST accept
and process both the 'textWithoutLanguage' and 'textWithLanguage' forms.
Similarly, for each attribute that the IPP object supports whose
attribute syntax is 'name', the IPP object MUST accept and process both
the 'nameWithoutLanguage' and 'nameWithLanguage' forms.  Furthermore, an
IPP object MUST return attributes to the client in operation responses
that conform to the syntax specified in Section 4.1, including their
full range if supplied previously by a client.


5.3 Charset and Natural Language Requirements


All clients and IPP objects MUST support the 'utf-8' charset as defined
in section 4.1.7.



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IPP objects MUST be able to accept any client request which correctly
uses the "attributes-natural-language" operation attribute or the
Natural Language Override mechanism on any individual attribute whether
or not the natural language is supported by the IPP object.  If an IPP
object supports a natural language, then it MUST be able to translate
(perhaps by table lookup) all generated 'text' or 'name' attribute
values into one of the supported languages (see section 3.1.4).  That
is, the IPP object that supports a natural language NEED NOT be a
general purpose translator of any arbitrary 'text' or 'name' value
supplied by the client into that natural language.  However, the object
MUST be able to translate (automatically generate) any of its own
attribute values and messages into that natural language.


5.4 Security Conformance Requirements


Conforming IPP Printer objects SHOULD support Transport Layer Security
(TLS) protocol Version 1 (TLS) [RFC2246] access,  MAY support access
without TLS, or MAY support both means of access.

Conforming IPP clients SHOULD support TLS access and non-TLS access.
Note: This client recommendation to support both means that conforming
IPP clients will be able to inter-operate with any IPP Printer object.

For a detailed discussion of security considerations and the IPP
application security profile required for TLS support, see section 8.



6. IANA Considerations (registered and private extensions)


This section describes how IPP can be extended to allow the following
registered and private extensions to IPP:

  1. keyword attribute values
  2. enum attribute values
  3. attributes
  4. attribute syntaxes
  5. operations
  6. attribute groups
  7. status codes


Extensions registered for use with IPP/1.1 are OPTIONAL for client and
IPP object conformance to the IPP/1.1 Model specification.

These extension procedures are aligned with the guidelines as set forth
by the IESG [IANA-CON].  Section 12 describes how to propose new
registrations for consideration.  IANA will reject registration
proposals that leave out required information or do not follow the
appropriate format described in Section 12.  IPP/1.1 may also be
extended by an appropriate RFC that specifies any of the above
extensions.



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6.1 Typed 'keyword' and 'enum' Extensions


IPP allows for 'keyword' and 'enum' extensions (see sections 4.1.2.3 and
4.1.4).  This document uses prefixes to the 'keyword' and 'enum' basic
attribute syntax type in order to communicate extra information to the
reader through its name. This extra information is not represented in
the protocol because it is unimportant to a client or Printer object.
The list below describes the prefixes and their meaning.

  "type1":  The IPP specification must be revised to add a new keyword
     or a new enum.  No private keywords or enums are allowed.

  "type2":  Implementers can, at any time, add new keyword or enum
     values by proposing the complete specification to IANA:

     iana@iana.org

     IANA will forward the registration proposal to the IPP Designated
     Expert who will review the proposal with a mailing list that the
     Designated Expert keeps for this purpose.  Initially, that list
     will be the mailing list used by the IPP WG:

          ipp@pwg.org

     even after the IPP WG is disbanded as permitted by [IANA-CON].  The
     IPP Designated Expert is appointed by the IESG Area Director
     responsible for IPP, according to [IANA-CON].

     When a type2 keyword or enum is approved, the IPP Designated Expert
     becomes the point of contact for any future maintenance that might
     be required for that registration.

  "type3":  Implementers can, at any time, add new keyword and enum
     values by submitting the complete specification to IANA as for
     type2 who will forward the proposal to the IPP Designated Expert.
     While no additional technical review is required, the IPP
     Designated Expert may, at his/her discretion, forward the proposal
     to the same mailing list as for type2 registrations for advice and
     comment.

     When a type3 keyword or enum is approved by the IPP Designated
     Expert, the original proposer becomes the point of contact for any
     future maintenance that might be required for that registration.


For type2 and type3 keywords, the proposer includes the name of the
keyword in the registration proposal and the name is part of the
technical review.

After type2 and type3 enums specifications are approved, the IPP
Designated Expert in consultation with IANA assigns the next available
enum number for each enum value.




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IANA will publish approved type2 and type3 keyword and enum attributes
value registration specifications in:

     ftp.isi.edu/iana/assignments/ipp/attribute-values/xxx/yyy.txt

where xxx is the attribute name that specifies the initial values and
yyy.txt is a descriptive file name that contains one or more enums or
keywords approved at the same time.  For example, if several additional
enums for stapling are approved for use with the "finishings" attribute
(and "finishings-default" and "finishings-supported" attributes), IANA
will publish the additional values in the file:

     ftp.isi.edu/iana/assignments/ipp/attribute-
     values/finishings/stapling.txt.

Note: Some attributes are defined to be: 'type3 keywords' | 'name' which
allows for attribute values to be extended by a site administrator with
administrator defined names.  Such names are not registered with IANA.

By definition, each of the three types above assert some sort of
registry or review process in order for extensions to be considered
valid.  Each higher numbered level (1, 2, 3) tends to be decreasingly
less stringent than the previous level.   Therefore, any typeN value MAY
be registered using a process for some typeM where M is less than N,
however such registration is NOT REQUIRED.  For example, a type3 value
MAY be registered in a type 1 manner (by being included in a future
version of an IPP specification), however, it is NOT REQUIRED.

This specification defines keyword and enum values for all of the above
types, including type3 keywords.

For private (unregistered) keyword extensions, implementers SHOULD use
keywords with a suitable distinguishing prefix, such as "xxx-" where xxx
is the (lowercase) fully qualified company name registered with IANA for
use in domain names [RFC1035].  For example, if the company XYZ Corp.
had obtained the domain name "XYZ.com", then a private keyword 'abc'
would be: 'xyz.com-abc'.

Note: RFC 1035 [RFC1035] indicates that while upper and lower case
letters are allowed in domain names, no significance is attached to the
case.  That is, two names with the same spelling but different case are
to be treated as if identical.  Also, the labels in a domain name must
follow the rules for ARPANET host names:  They must start with a letter,
end with a letter or digit, and have as interior characters only
letters, digits, and hyphen.  Labels must be 63 characters or less.
Labels are separated by the "." character.

For private (unregistered) enum extension, implementers MUST use values
in the reserved integer range which is 2**30 to 2**31-1.






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6.2 Attribute Extensibility


Attribute names are type2 keywords.  Therefore, new attributes may be
registered and have the same status as attributes in this document by
following the type2 extension rules.  For private (unregistered)
attribute extensions, implementers SHOULD use keywords with a suitable
distinguishing prefix as described in Section 6.1.

IANA will publish approved attribute registration specifications as
separate files:

     ftp.isi.edu/iana/assignments/ipp/attributes/xxx-yyy.txt

where "xxx-yyy" is the new attribute name.

If a new Printer object attribute is defined and its values can be
affected by a specific document format, its specification needs to
contain the following sentence:

  "The value of this attribute returned in a Get-Printer-
  Attributes response MAY depend on the "document-format"
  attribute supplied (see Section 3.2.5.1)."

If the specification does not, then its value in the Get-Printer-
Attributes response MUST NOT depend on the "document-format" supplied in
the request.  When a new Job Template attribute is registered, the value
of the Printer attributes MAY vary with "document-format" supplied in
the request without the specification having to indicate so.


6.3 Attribute Syntax Extensibility


Attribute syntaxes are like type2 enums.  Therefore, new attribute
syntaxes may be registered and have the same status as attribute
syntaxes in this document by following the type2 extension rules
described in Section 6.1.  The value codes that identify each of the
attribute syntaxes are assigned in the "Encoding and Transport"
specification [IPP-PRO], including a designated range for private,
experimental use.

For attribute syntaxes, the IPP Designated Expert in consultation with
IANA assigns the next attribute syntax code in the appropriate range as
specified in [IPP-PRO].  IANA will publish approved attribute syntax
registration specifications as separate files:

     ftp.isi.edu/iana/assignments/ipp/attribute-syntaxes/xxx-yyy.txt

where 'xxx-yyy' is the new attribute syntax name.







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6.4 Operation Extensibility


Operations may also be registered following the type2 procedures
described in Section 6.1, though major new operations will usually be
done by a new standards track RFC that augments this document.  For
private (unregistered) operation extensions, implementers MUST use the
range for the "operation-id" in requests specified in Section 4.4.13
"operations-supported" Printer attribute.

For operations, the IPP Designated Expert in consultation with IANA
assigns the next operation-id code as specified in Section 4.4.13.  IANA
will publish approved operation registration specifications as separate
files:

     ftp.isi.edu/iana/assignments/ipp/operations/Xxx-Yyy.txt

where "Xxx-Yyy" is the new operation name.


6.5 Attribute Groups


Attribute groups passed in requests and responses may be registered
following the type2 procedures described in Section 6.1.  The tags that
identify each of the attribute groups are assigned in [IPP-PRO].

For attribute groups, the IPP Designated Expert in consultation with
IANA assigns the next attribute group tag code in the appropriate range
as specified in [IPP-PRO].  IANA will publish approved attribute group
registration specifications as separate files:

     ftp.isi.edu/iana/assignments/ipp/attribute-group-tags/xxx-yyy-
     tag.txt

where 'xxx-yyy-tag' is the new attribute group tag name.


6.6 Status Code Extensibility


Operation status codes may also be registered following the type2
procedures described in Section 6.1.  The values for status codes are
allocated in ranges as specified in Section 14 for each status code
class:

  "informational" - Request received, continuing process
  "successful" - The action was successfully received, understood, and
     accepted
  "redirection" - Further action must be taken in order to complete the
     request
  "client-error" - The request contains bad syntax or cannot be
     fulfilled
  "server-error" - The IPP object  failed to fulfill an apparently
     valid request



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For private (unregistered) operation status code extensions,
implementers MUST use the top of each range as specified in Section 14.

For operation status codes, the IPP Designated Expert in consultation
with IANA assigns the next status code in the appropriate class range as
specified in Section 14.  IANA will publish approved status code
registration specifications as separate files:

     ftp.isi.edu/iana/assignments/ipp/status-codes/xxx-yyy.txt

where "xxx-yyy" is the new operation status code keyword.


6.7 Registration of MIME types/sub-types for document-formats


The "document-format" attribute's syntax is 'mimeMediaType'.  This means
that valid values are Internet Media Types (see Section 4.1.9).  RFC
2045 [RFC2045] defines the syntax for valid Internet media types.  IANA
is the registry for all Internet media types.


6.8 Registration of charsets for use in 'charset' attribute values

The "attributes-charset" attribute's syntax is 'charset'.  This means
that valid values are charsets names.  When a charset in the IANA
registry has more than one name (alias), the name labeled as "(preferred
MIME name)", if present, MUST be used (see Section 4.1.7).  IANA is the
registry for charsets following the procedures of [RFC2278].


7. Internationalization Considerations


Some of the attributes have values that are text strings and names which
are intended for human understanding rather than machine understanding
(see the 'text' and 'name' attribute syntaxes in Sections 4.1.1 and
4.1.2).

In each operation request, the client

  - identifies the charset and natural language of the request which
     affects each supplied 'text' and 'name' attribute value, and
  - requests the charset and natural language for attributes returned
     by the IPP object in operation responses (as described in Section
     3.1.4.1).


In addition, the client MAY separately and individually identify the
Natural Language Override of a supplied 'text' or 'name' attribute using
the 'textWithLanguage' and 'nameWithLanguage' technique described
section 4.1.1.2 and 4.1.2.2 respectively.

All IPP objects MUST support the UTF-8 [RFC2279] charset in all 'text'
and 'name' attributes supported.  If an IPP object supports more than
the UTF-8 charset, the object MUST convert between them in order to
return the requested charset to the client according to Section 3.1.4.2.

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If an IPP object supports more than one natural language, the object
SHOULD return 'text' and 'name' values in the natural language requested
where those values are generated by the Printer (see Section 3.1.4.1).

For Printers that support multiple charsets and/or multiple natural
languages in 'text' and 'name' attributes, different jobs may have been
submitted in differing charsets and/or natural languages.  All responses
MUST be returned in the charset requested by the client.  However, the
Get-Jobs operation uses the 'textWithLanguage' and 'nameWithLanguage'
mechanism to identify the differing natural languages with each job
attribute returned.

The Printer object also has configured charset and natural language
attributes.   The client can query the Printer object to determine the
list of charsets and natural languages supported by the Printer object
and what the Printer object's configured values are.  See the "charset-
configured", "charset-supported", "natural-language-configured", and
"generated-natural-language-supported" Printer description attributes
for more details.

The "charset-supported" attributed identifies the supported charsets.
If a charset is supported, the IPP object MUST be capable of converting
to and from that charset into any other supported charset.  In many
cases, an IPP object will support only one charset and it MUST be the
UTF-8 charset.

The "charset-configured" attribute identifies the one supported charset
which is the native charset given the current configuration of the IPP
object (administrator defined).

The "generated-natural-language-supported" attribute identifies the set
of supported natural languages for generated messages; it is not related
to the set of natural languages that must be accepted for client
supplied 'text' and 'name' attributes.  For client supplied 'text' and
'name' attributes, an IPP object MUST accept ALL supplied natural
languages.  Just because a Printer object is currently configured to
support 'en-us' natural language does not mean that the Printer object
should reject a job if the client supplies a job name that is in 'fr-
ca'.

The "natural-language-configured" attribute identifies the one supported
natural language for generated messages which is the native natural
language given the current configuration of the IPP object
(administrator defined).

Attributes of type 'text' and 'name' are populated from different
sources.  These attributes can be categorized into following groups
(depending on the source of the attribute):

  1. Some attributes are supplied by the client (e.g., the client
     supplied "job-name", "document-name", and "requesting-user-name"
     operation attributes along with the corresponding Job object's
     "job-name" and "job-originating-user-name" attributes).  The IPP



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     object MUST accept these attributes in any natural language no
     matter what the set of supported languages for generated messages
  2. Some attributes are supplied by the system administrator (e.g.,
     the Printer object's "printer-name" and "printer-location"
     attributes).  These too can be in any natural language.  If the
     natural language for these attributes is different than what a
     client requests, then they must be reported using the Natural
     Language Override mechanism.
  3. Some attributes are supplied by the device manufacturer (e.g., the
     Printer object's "printer-make-and-model" attribute).  These too
     can be in any natural language.  If the natural language for these
     attributes is different than what a client requests, then they must
     be reported using the Natural Language Override mechanism.
  4. Some attributes are supplied by the operator (e.g., the Job
     object's "job-message-from-operator" attribute). These too can be
     in any natural language.  If the natural language for these
     attributes is different than what a client requests, then they must
     be reported using the Natural Language Override mechanism.
  5. Some attributes are generated by the IPP object (e.g., the Job
     object's "job-state-message" attribute, the Printer object's
     "printer-state-message" attribute, and the "status-message"
     operation attribute).  These attributes can only be in one of  the
     "generated-natural-language-supported" natural languages.  If a
     client requests some natural language for these attributes other
     than one of the supported values, the IPP object SHOULD respond
     using the value of the "natural-language-configured" attribute
     (using the Natural Language Override mechanism if needed).


The 'text' and 'name' attributes specified in this version of this
document (additional ones will be registered according to the procedures
in Section 6) are:

  Attributes                      Source
  --------------------------      ----------
  Operation Attributes
     job-name (name)               client
     document-name (name)          client
     requesting-user-name (name)   client
     status-message                Job or Printer object

  Job Template Attributes:
     job-hold-until (keyword | name)    client matches administrator-
  configured
     job-hold-until-default (keyword | name) client matches
  administrator-configured
     job-hold-until-supported (keyword | name)    client matches
  administrator-configured
     job-sheets (keyword | name)   client matches administrator-
  configured
     job-sheets-default (keyword | name)     client matches
  administrator-configured
     job-sheets-supported (keyword | name)   client matches
  administrator-configured


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     media (keyword | name)        client matches administrator-
  configured
     media-default (keyword | name)     client matches administrator-
  configured
     media-supported (keyword | name)   client matches administrator-
  configured
     media-ready (keyword | name)  client matches administrator-
  configured

  Job Description Attributes:
     job-name (name)               client or Printer object
     job-originating-user-name (name)   Printer object
     job-state-message (text)      Job or Printer object
     output-device-assigned (name(127)) administrator
     job-message-from-operator (text(127))   operator

  Printer Description Attributes:
     printer-name (name(127))      administrator
     printer-location (text(127))  administrator
     printer-info (text(127))      administrator
     printer-make-and-model (text(127)) administrator or manufacturer
     printer-state-message (text)  Printer object
     printer-message-from-operator (text(127))    operator


8. Security Considerations


IPP objects SHOULD be deployed over protocol stacks that support the
Transport Layer Security (TLS) protocol [RFC2246].  Other IPP objects
MAY be deployed over protocol stacks that do not support TLS.  Some IPP
objects MAY be deployed over both types of protocol stacks.  Those IPP
objects that support TLS, are capable of supporting mutual
authentication as well as privacy of messages via multiple encryption
schemes.  An important point about security related information for TLS
access to an IPP object, is that the security-related parameters
(authentication, encryption keys, etc.) are "out-of-band" to the actual
IPP protocol.

An IPP object that does not support TLS MAY elect to support a transport
layer that provides other security mechanisms.  For example, in a
mapping of IPP over HTTP/1.1 [IPP-PRO], if the IPP object does not
support TLS, HTTP still allows for client authentication using Digest
Access Authentication (DAA) [RFC2069].

It is difficult to anticipate the security risks that might exist in any
given IPP environment. For example, if IPP is used within a given
corporation over a private network, the risks of exposing document data
may be low enough that the corporation will choose not to use encryption
on that data.  However, if the connection between the client and the IPP
object is over a public network, the client may wish to protect the
content of the information during transmission through the network with
encryption.



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Furthermore, the value of the information being printed may vary from
one IPP environment to the next. Printing payroll checks, for example,
would have a different value than printing public information from a
file.  There is also the possibly of denial-of-service attacks, but
denial-of-service attacks against printing resources are not well
understood and there is no published precedents regarding this scenario.

Once the authenticated identity of the requester has been supplied to
the IPP object, the object uses that identity to enforce any
authorization policy that might be in place.  For example, one site's
policy might be that only the job owner is allowed to cancel a job.  The
details and mechanisms to set up a particular access control policy are
not part of IPP/1.1, and must be established via some other type of
administrative or access control framework.  However, there are
operation status codes that allow an IPP server to return information
back to a client about any potential access control violations for an
IPP object.

During a create operation, the client's identity is recorded in the Job
object in an implementation-defined attribute.  This information can be
used to verify a client's identity for subsequent operations on that Job
object in order to enforce any access control policy that might be in
effect.  See section 8.3 below for more details.

Since the security levels or the specific threats that any given IPP
system administrator may be concerned with cannot be anticipated, IPP
MUST be capable of operating with different security mechanisms and
security policies as required by the individual installation. Security
policies might vary from very strong, to very weak, to none at all, and
corresponding security mechanisms will be required. TLS supports the
type of negotiated levels of security required by most, if not all,
potential IPP environments. IPP environments that require no security
can elect to deploy IPP objects that do not utilize the optional TLS
security mechanisms.


8.1 Security Scenarios


The following sections describe specific security attacks for IPP
environments.  Where examples are provided they should be considered
illustrative of the environment and not an exhaustive set. Not all of
these environments will necessarily be addressed in initial
implementations of IPP.


8.1.1 Client and Server in the Same Security Domain

This environment is typical of internal networks where traditional
office workers print the output of personal productivity applications on
shared work-group printers, or where batch applications print their
output on large production printers. Although the identity of the user
may be trusted in this environment, a user might want to protect the
content of a document against such attacks as eavesdropping, replaying
or tampering.


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8.1.2 Client and Server in Different Security Domains

Examples of this environment include printing a document created by the
client on a publicly available printer, such as at a commercial print
shop; or printing a document remotely on a business associate's printer.
This latter operation is functionally equivalent to sending the document
to the business associate as a facsimile. Printing sensitive information
on a Printer in a different security domain requires strong security
measures. In this environment authentication of the printer is required
as well as protection against unauthorized use of print resources. Since
the document crosses security domains, protection against eavesdropping
and document tampering are also required. It will also be important in
this environment to protect Printers against "spamming" and malicious
document content.


8.1.3 Print by Reference

When the document is not stored on the client, printing can be done by
reference. That is, the print request can contain a reference, or
pointer, to the document instead of the actual document itself. Standard
methods currently do not exist for remote entities to "assume" the
credentials of a client for forwarding requests to a 3rd party. It is
anticipated that Print-By-Reference will be used to access "public"
documents and that sophisticated methods for authenticating "proxies"
will not be specified for version 1 of IPP.


8.2 URIs for TLS and non-TLS Access


As described earlier, an IPP object SHOULD support TLS access, MAY non-
TLS access, or both.  The "printer-uri-supported" attribute contains the
Printer object's URI(s).  Its companion attribute, "uri-security-
supported", identifies the security mechanism used for each URI listed
in the "printer-uri-supported" attribute.  For each Printer operation
request, a client MUST supply only one URI in the "printer-uri"
operation attribute.  In other words, even though the Printer supports
more than one URI, the client only interacts with the Printer object
using one if its URIs.  This duality is not needed for Job objects,
since the Printer objects is the factory for Job objects, and the
Printer object will generate the correct URI for new Job objects
depending on the Printer object's security configuration.


8.3 The "requesting-user-name" (name(MAX)) Operation Attribute


Each operation MUST specify the user who is performing the operation in
both of the following two ways:

  1) via the REQUIRED "requesting-user-name" operation attribute that a
     client SHOULD supply in all operations. The client MUST obtain the
     value for this attribute from an environmental or network login
     name for the user, rather than allowing the user to supply any
     value. If the client does not supply a value for "requesting-user-


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     name", the printer MUST assume that the client is supplying some
     anonymous name, such as "anonymous".
  2) via an authentication mechanism of the underlying transport which
     may be configured to give no authentication information.


There are six cases to consider:

  a)  the authentication mechanism gives no information, and the client
     doesn't specify  "requesting-user-name".
  b)  the authentication mechanism gives no information, but the client
     specifies "requesting-user-name".
  c)  the authentication mechanism specifies a user which has no human
     readable representation, and the client  doesn't specify
     "requesting-user-name".
  d)  the authentication mechanism specifies a user which has no human
     readable representation, but the client specifies "requesting-user-
     name".
  e)  the authentication mechanism specifies a user which has a human
     readable representation. The Printer object ignores the
     "requesting-user-name".
  f)  the authentication mechanism specifies a user who is trusted and
     whose name means that the value of the "requesting-user-name",
     which MUST be present, is treated as the authenticated name.


Note:  Case "f" is intended for a tightly coupled gateway and server to
work together so that the "user" name is able to be that of the gateway
client and not that of the gateway.  Because most, if not all, system
vendors will initially implement IPP via a gateway into their existing
print system, this mechanism is necessary unless the authentication
mechanism allows a gateway (client) to act on behalf of some other
client.

The user-name has two forms:

  - one that is human readable: it is held in the REQUIRED "job-
     originating-user-name" Job Description attribute which is set
     during the job creation operations. It is used for presentation
     only, such as returning in queries or printing on start sheets
  - one for authorization: it is held in an undefined (by IPP) Job
     object attribute which is set by the job creation operation.  It is
     used to authorize other operations, such as Send-Document, Send-
     URI, Cancel-Job, to determine the user when the "my-jobs" attribute
     is specified with Get-Jobs, and to limit what attributes and values
     to return with Get-Job-Attributes and Get-Jobs.


The human readable user name:

  - is the value of the "requesting-user-name" for cases b, d and f.
  - comes from the authentication mechanism for case e
  - is some anonymous name, such as "anonymous" for cases a and c.


The user name used for authorization:

  - is the value of the "requesting-user-name" for cases b  and f.

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  - comes from the authentication mechanism for cases c, d and  e
  - is some anonymous name, such as "anonymous" for case a.


The essence of these rules for resolving conflicting sources of user-
names is that a printer implementation is free to pick either source as
long as it achieves consistent results.  That is, if a user uses the
same path for a series of requests, the requests MUST appear to come
from the same user from the standpoint of both the human-readable user
name and the user name for authorization.  This rule MUST continue to
apply even if a request could be authenticated by two or more
mechanisms.  It doesn't matter which of  several authentication
mechanisms a Printer uses as long as it achieves consistent results.  If
a client uses more than one authentication mechanism, it is recommended
that an administrator make all credentials resolve to the same user and
user-name as much as possible.


8.4 Restricted Queries


In many IPP operations, a client supplies a list of attributes to be
returned in the response.  For security reasons, an IPP object may be
configured not to return all attributes (or all values) that a client
requests.  The job attributes returned MAY depend on whether the
requesting user is the same as the user that submitted the job. The IPP
object MAY even return none of the requested attributes. In such cases,
the status returned is the same as if the object had returned all
requested attributes.  The client cannot tell by such a response whether
the requested attribute was present or absent on the object.


8.5 Operations performed by operators and system administrators

For the three printer operations Pause-Printer, Resume-Printer, and
Purge-Jobs (see sections 3.2.7, 3.2.8 and 3.2.9), the requesting user is
intended to be an operator or administrator of the Printer object (see
section 1).  The means for authorizing an operator or administrator of
the Printer object are not specified in this document.

8.6 Queries on jobs submitted using non-IPP protocols


If the device that an IPP Printer is representing is able to accept jobs
using other job submission protocols in addition to IPP, it is
RECOMMENDED that such an implementation at least allow such "foreign"
jobs to be queried using Get-Jobs returning "job-id" and "job-uri" as
'unknown'.  Such an implementation NEED NOT support all of the same IPP
job attributes as for IPP jobs.  The IPP object returns the 'unknown'
out-of-band value for any requested attribute of a foreign job that is
supported for IPP jobs, but not for foreign jobs.

It is further RECOMMENDED, that the IPP Printer generate "job-id" and
"job-uri" values for such "foreign jobs", if possible, so that they may
be targets of other IPP operations, such as Get-Job-Attributes and
Cancel-Job.  Such an implementation also needs to deal with the problem


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of authentication of such foreign jobs.  One approach would be to treat
all such foreign jobs as belonging to users other than the user of the
IPP client.  Another approach would be for the foreign job to belong to
'anonymous'.  Only if the IPP client has been authenticated as an
operator or administrator of the IPP Printer object, could the foreign
jobs be queried by an IPP request.  Alternatively, if the security
policy is to allow users to query other users' jobs, then the foreign
jobs would also be visible to an end-user IPP client using Get-Jobs and
Get-Job-Attributes.


8.7 IPP Security Application Profile for TLS


     The IPP application profile for TLS follows the standard "Mandatory
     Cipher Suites"  requirement as documented in the TLS specification
     [RFC2246].

If a conforming IPP object supports TLS, it MUST implement and support
the "Mandatory Cipher Suites" as specified in the TLS specification
[RFC2246] and MAY support additional cipher suites.

A conforming IPP client SHOULD support TLS including the "Mandatory
Cipher Suites" as specified in the TLS specification [RFC2246].  A
conforming IPP client MAY support additional cipher suites.  Client
implementations MUST NOT assume any other cipher suites are supported by
an IPP Printer object.



9. See the TLS specification [RFC2246] for a discussion of any
government export restrictions on implementations conforming to the
"Mandatory Cipher Suites".  References

[ASCII]
     Coded Character Set - 7-bit American Standard Code for Information
     Interchange (ASCII), ANSI X3.4-1986. This standard is the
     specification of the US-ASCII charset.

[BCP-11]
     Bradner S., Hovey R., "The Organizations Involved in the IETF
     Standards Process", 1996/10/29 (RFC 2028)

[HTPP]
     J. Barnett, K. Carter, R. DeBry,  "Initial Draft - Hypertext
     Printing Protocol - HTPP/1.0", October 1996,
     ftp://ftp.pwg.org/pub/pwg/ipp/historic/htpp/overview.ps.gz

[IANA-CON]
     Narte, T. and Alvestrand, H.T.:  Guidelines for Writing an IANA
     Considerations Section in RFCs, Work in Progress, draft-iesg-iana-
     considerations-04.txt, May 21, 1998.





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[IANA-CS]
     IANA Registry of Coded Character Sets: ftp://ftp.isi.edu/in-
     notes/iana/assignments/character-sets

[IANA-MT]
     IANA Registry of Media Types:  ftp://ftp.isi.edu/in-
     notes/iana/assignments/media-types/

[IPP-IIG]
     Hastings, T., Manros, C., "Internet Printing Protocol/1.1:  draft-
     ietf-ipp-implementers-guide-v11-??.txt, ?? 1999, work in progress.

[IPP-IIG1.0]
     Hastings, T., Manros, C., "Internet Printing Protocol/1.0:
     Implementer's Guide", draft-ietf-ipp-implementers-guide-01.txt,
     February 1999, work in progress.

[IPP LPD]
     Herriot, R., Hastings, T., Jacobs, N., Martin, J., "Mapping between
     LPD and IPP Protocols", draft-ietf-ipp-lpd-ipp-map-05.txt, November
     1998.

[IPP-MOD1.0]
     R. deBry, T. Hastings, R. Herriot, S. Isaacson, P. Powell,
     "Internet Printing Protocol/1.0: Model and Semantics", draft-ietf-
     ipp-model-11.txt, November, 1998.

[IPP-PRO]
     Herriot, R., Butler, S., Moore, P., Tuner, R., "Internet Printing
     Protocol/1.1: Encoding and Transport", draft-ietf-ipp-protocol-v11-
     00.txt, February, 1999.

[IPP-PRO1.0]
     Herriot, R., Butler, S., Moore, P., Tuner, R., "Internet Printing
     Protocol/1.0: Encoding and Transport", draft-ietf-ipp-protocol-
     07.txt, November, 1998.

[IPP-RAT]
     Zilles, S., "Rationale for the Structure and Model and Protocol for
     the Internet Printing Protocol", draft-ietf-ipp-rat-04.txt,
     November, 1998.

[IPP-REQ]
     Wright, D., "Design Goals for an Internet Printing Protocol",
     draft-ietf-ipp-req-03.txt, November, 1998.

[ISO10646-1]
     ISO/IEC 10646-1:1993, "Information technology -- Universal
     Multiple-Octet Coded Character Set (UCS) - Part 1: Architecture and
     Basic Multilingual Plane, JTC1/SC2."

[ISO8859-1]
     ISO/IEC 8859-1:1987, "Information technology -- 8-bit One-Byte
     Coded Character Set - Part 1: Latin Alphabet Nr 1", 1987, JTC1/SC2.

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[ISO10175]
     ISO/IEC 10175 Document Printing Application (DPA), June 1996.

[LDPA]
     T. Hastings,  S. Isaacson,  M. MacKay, C. Manros, D. Taylor, P.
     Zehler,  "LDPA - Lightweight Document Printing Application",
     October 1996,
     ftp://ftp.pwg.org/pub/pwg/ipp/historic/ldpa/ldpa8.pdf.gz

[P1387.4]
     Kirk, M. (editor), POSIX System Administration - Part 4: Printing
     Interfaces, POSIX 1387.4 D8, 1994.

[PSIS]    Herriot, R. (editor), X/Open A Printing System
     Interoperability Specification (PSIS), August 1995.

[PWG]
     Printer Working Group, http://www.pwg.org.

[RFC1035]
     P. Mockapetris, "DOMAIN NAMES - IMPLEMENTATION AND SPECIFICATION",
     RFC 1035, November 1987.

[RFC1179]
     McLaughlin, L. III, (editor), "Line Printer Daemon Protocol" RFC
     1179, August 1990.

[RFC1759]
     Smith, R., Wright, F., Hastings, T., Zilles, S., and Gyllenskog,
     J., "Printer MIB", RFC 1759, March 1995.

[RFC1766]
     H. Alvestrand, "Tags for the Identification of Languages", RFC
     1766, March 1995.

[RFC1903]
     J. Case, et.al., "Textual Conventions for Version 2 of the Simple
     Network Management Protocol (SNMP v2)" RFC 1903, January 1996.

[RFC1952]
     P. Deutsch, "GZIP file format specification version 4.3", RFC 1952,
     May 1996.

[RFC2026]
     S. Bradner, "The Internet Standards Process -- Revision 3", RFC
     2026, October 1996.

[RFC2045]
     N. Fried, N. Borenstein, ", Multipurpose Internet Mail Extensions
     (MIME) Part One: Format of Internet Message Bodies " RFC 2045,
     November 1996.




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[RFC2046]
     Multipurpose Internet Mail Extensions (MIME) Part Two: Media Types.
     N. Freed & N. Borenstein. November 1996. (Obsoletes RFC1521,
     RFC1522, RFC1590), RFC 2046.

[RFC2048]
     N. Freed, J. Klensin & J. Postel, "Multipurpose Internet Mail
     Extension (MIME) Part Four: Registration Procedures". RFC 2048,
     November 1996.

[RFC2068]
     R. Fielding, J. Gettys, J. Mogul, H. Frystyk, T. Berners-Lee,
     "Hypertext Transfer Protocol - HTTP/1.1", RFC 2068, January 1997

[RFC2069]
     J. Franks, P. Hallam-Baker, J. Hostetler, P. Leach, A. Luotonen, E.
     Sink, L. Stewart, "An Extension to HTTP: Digest Access
     Authentication", RFC-2069, Jan 1997.

[RFC2119]
     S. Bradner, "Key words for use in RFCs to Indicate Requirement
     Levels", RFC 2119 , March 1997

[RFC2228]
     M. Horowitz, S. Lunt, "FTP Security Extensions", RFC 2228, October
     1997.

[RFC2246]
     T. Dierks, C. Allen, "The TLS Protocol Version 1.0", RFC 2246,
     January 1999.

[RFC2277]
     H. Alvestrand, "IETF Policy on Character Sets and Languages" RFC
     2277, January 1998.

[RFC2278]
     N. Freed, J. Postel:  "IANA CharSet Registration Procedures", RFC
     2278, January 1998.

[RFC2279]
     F. Yergeau , "UTF-8, a transformation format of ISO 10646", RFC
     2279. January 1998.

[RFC2316]
     S. Bellovin , "Report of the IAB Security Architecture Workshop",
     RFC 2316, April 1998.

[RFC2396]
     Berners-Lee, T., Fielding, R., Masinter, L., "Uniform Resource
     Identifiers (URI): Generic Syntax", RFC 2396, August 1998.

[SSL]
     Netscape, The SSL Protocol, Version 3, (Text version 3.02),
     November 1996.

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[SWP]
     P. Moore, B. Jahromi, S. Butler, "Simple Web Printing SWP/1.0", May
     7, 1997, ftp://ftp.pwg.org/pub/pwg/ipp/new_PRO/swp9705.pdf



10. Notices


The IETF takes no position regarding the validity or scope of any
intellectual property or other rights that might be claimed to  pertain
to the implementation or use of the technology described in this
document or the extent to which any license under such rights might or
might not be available; neither does it represent that it has made any
effort to identify any such rights.  Information on the IETF's
procedures with respect to rights in standards-track and standards-
related documentation can be found in BCP-11[BCP-11].  Copies of claims
of rights made available for publication and any assurances of licenses
to be made available, or the result of an attempt made to obtain a
general license or permission for the use of such proprietary rights by
implementers or users of this specification can be obtained from the
IETF Secretariat.

The IETF invites any interested party to bring to its attention any
copyrights, patents or patent applications, or other proprietary rights
which may cover technology that may be required to practice this
standard.  Please address the information to the IETF Executive
Director.

Copyright (C) The Internet Society (1999). All Rights Reserved.

This document and translations of it may be copied and furnished to
others, and derivative works that comment on or otherwise explain it or
assist in its implementation may be prepared, copied, published and
distributed, in whole or in part, without restriction of any kind,
provided that the above copyright notice and this paragraph are included
on all such copies and derivative works.  However, this document itself
may not be modified in any way, such as by removing the copyright notice
or references to the Internet Society or other Internet organizations,
except as needed for the  purpose of developing Internet standards in
which case the procedures for copyrights defined in the Internet
Standards process must be followed, or as required to translate it into
languages other than English.

The limited permissions granted above are perpetual and will not be
revoked by the Internet Society or its successors or assigns.

This document and the information contained herein is provided on an "AS
IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK
FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT
LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT
INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR
FITNESS FOR A PARTICULAR PURPOSE.



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11. Author's Address

     Scott A. Isaacson (Editor)
     Novell, Inc.
     122 E 1700 S
     Provo, UT   84606

     Phone: 801-861-7366
     Fax:   801-861-2517
     e-mail: sisaacson@novell.com

     Tom Hastings
     Xerox Corporation
     737 Hawaii St.  ESAE 231
     El Segundo, CA   90245

     Phone: 310-333-6413
     Fax:   310-333-5514
     e-mail: hastings@cp10.es.xerox.com

     Robert Herriot
     Xerox Corp.
     3400 Hill View Ave, Building 1
     Palo Alto, CA 94304

     Phone: 650-813-7696
     Fax:  650-813-6860
     e-mail: robert.herriot@pahv.xerox.com

     Roger deBry
     HUC/003G
     IBM Corporation
     P.O. Box 1900
     Boulder, CO 80301-9191

     Phone: (303) 924-4080
     Fax: (303) 924-9889
     e-mail: debry@vnet.ibm.com

     Patrick Powell
     Astart Technologies
     9475 Chesapeake Dr., Suite D
     San Diego, CA  95123

     Phone: (619) 874-6543
     Fax: (619) 279-8424
     e-mail: papowell@astart.com

     IPP Mailing List:  ipp@pwg.org
     IPP Mailing List Subscription: ipp-request@pwg.org
     IPP Web Page:  http://www.pwg.org/ipp/

Implementers of this specification are encouraged to join IPP Mailing
List in order to participate in any discussions of clarification issues

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and review of registration proposals for additional attributes and
values.

Other Participants:

     Chuck Adams - Tektronix
     Jeff Barnett - IBM
     Ron Bergman - Dataproducts Corp.
     Sylvan Butler - HP
     Keith Carter - IBM Corporation
     Jeff Copeland - QMS
     Andy Davidson - Tektronix
     Mabry Dozier - QMS
     Lee Farrell - Canon Information Systems
     Steve Gebert - IBM
     Babek Jahromi - Microsoft
     David Kellerman - Northlake Software
     Rick Landau - Digital
     Greg LeClair - Epson
     Harry Lewis - IBM
     Pete Loya - HP
     Ray Lutz - Cognisys
     Mike MacKay - Novell, Inc.
     Daniel Manchala - Xerox
     Carl-Uno Manros - Xerox
     Jay Martin - Underscore
     Larry Masinter - Xerox
     Stan McConnell - Xerox
     Ira McDonald - High North Inc.
     Paul Moore - Microsoft
     Tetsuya Morita - Ricoh
     Yuichi Niwa - Ricoh
     Pat Nogay - IBM
     Ron Norton - Printronics
     Bob Pentecost - HP
     Rob Rhoads - Intel
     Xavier Riley - Xerox
     David Roach - Unisys
     Stuart Rowley - Kyocera
     Hiroyuki Sato - Canon
     Bob Setterbo - Adobe
     Devon Taylor - Novell, Inc.
     Mike Timperman - Lexmark
     Randy Turner - Sharp
     Atsushi Yuki - Kyocera
     Rick Yardumian - Xerox
     Lloyd Young - Lexmark
     Bill Wagner - DPI
     Jim Walker - DAZEL
     Chris Wellens - Interworking Labs
     Rob Whittle - Novell, Inc.
     Don Wright - Lexmark
     Peter Zehler - Xerox
     Steve Zilles - Adobe


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12. Formats for IPP Registration Proposals

In order to propose an IPP extension for registration, the proposer must
submit an application to IANA by email to "iana@iana.org" or by filling
out the appropriate form on the IANA web pages (http://www.iana.org).
This section specifies the required information and the formats for
proposing registrations of extensions to IPP as provided in Section 6
for:

  1. type2 'keyword' attribute values
  2. type3 'keyword' attribute values
  3. type2 'enum' attribute values
  4. type3 'enum' attribute values
  5. attributes
  6. attribute syntaxes
  7. operations
  8. status codes

12.1 Type2 keyword attribute values registration

Type of registration:  type2 keyword attribute value
Name of attribute to which this keyword specification is to be added:
Proposed keyword name of this keyword value:
Specification of this keyword value (follow the style of IPP Model
Section 4.1.2.3):
Name of proposer:
Address of proposer:
Email address of proposer:

Note:  For type2 keywords, the Designated Expert will be the point of
contact for the approved registration specification, if any maintenance
of the registration specification is needed.

12.2 Type3 keyword attribute values registration

Type of registration:  type3 keyword attribute value
Name of attribute to which this keyword specification is to be added:
Proposed keyword name of this keyword value:
Specification of this keyword value (follow the style of IPP Model
Section 4.1.2.3):
Name of proposer:
Address of proposer:
Email address of proposer:

Note:  For type3 keywords, the proposer will be the point of contact for
the approved registration specification, if any maintenance of the
registration specification is needed.

12.3 Type2 enum attribute values registration

Type of registration:  type2 enum attribute value
Name of attribute to which this enum specification is to be added:
Keyword symbolic name of this enum value:


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Numeric value (to be assigned by the IPP Designated Expert in
consultation with IANA):
Specification of this enum value (follow the style of IPP Model Section
4.1.4):
Name of proposer:
Address of proposer:
Email address of proposer:

Note:  For type2 enums, the Designated Expert will be the point of
contact for the approved registration specification, if any maintenance
of the registration specification is needed.

12.4 Type3 enum attribute values registration

Type of registration:  type3 enum attribute value
Name of attribute to which this enum specification is to be added:
Keyword symbolic name of this enum value:
Numeric value (to be assigned by the IPP Designated Expert in
consultation with IANA):
Specification of this enum value (follow the style of IPP Model Section
4.1.4):
Name of proposer:
Address of proposer:
Email address of proposer:

Note:  For type3 enums, the proposer will be the point of contact for
the approved registration specification, if any maintenance of the
registration specification is needed.

12.5 Attribute registration

Type of registration:  attribute
Proposed keyword name of this attribute:
Types of attribute (Operation, Job Template, Job Description, Printer
Description):
Operations to be used with if the attribute is an operation attribute:
Object (Job, Printer, etc. if bound to an object):
Attribute syntax(es) (include 1setOf and range as in Section 4.2):
If attribute syntax is 'keyword' or 'enum', is it type2 or type3:
If this is a Printer attribute, MAY the value returned depend on
"document-format" (See Section 6.2):
If this is a Job Template attribute, how does its specification depend
on the value of the "multiple-document-handling" attribute:
Specification of this attribute (follow the style of IPP Model Section
4.2):
Name of proposer:
Address of proposer:
Email address of proposer:

Note:  For attributes, the IPP Designated Expert will be the point of
contact for the approved registration specification, if any maintenance
of the registration specification is needed.



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12.6 Attribute Syntax registration

Type of registration:  attribute syntax
Proposed name of this attribute syntax:
Type of attribute syntax (integer, octetString, character-string,  see
[IPP-PRO]):
Numeric value (to be assigned by the IPP Designated Expert in
consultation with IANA):
Specification of this attribute (follow the style of IPP Model Section
4.1):
Name of proposer:
Address of proposer:
Email address of proposer:

Note:  For attribute syntaxes, the IPP Designated Expert will be the
point of contact for the approved registration specification, if any
maintenance of the registration specification is needed.

12.7 Operation registration

Type of registration:  operation
Proposed name of this operation:
Numeric operation-id value (to be assigned by the IPP Designated Expert
in consultation with IANA):
Object Target (Job, Printer, etc. that operation is upon):
Specification of this attribute (follow the style of IPP Model Section
3):
Name of proposer:
Address of proposer:
Email address of proposer:

Note:  For operations, the IPP Designated Expert will be the point of
contact for the approved registration specification, if any maintenance
of the registration specification is needed.

12.8 Attribute Group registration

Type of registration:  attribute group
Proposed name of this attribute group:
Numeric tag according to [IPP-PRO] (to be assigned by the IPP Designated
Expert in consultation with IANA):
Operation requests and group number for each operation in which the
attribute group occurs:
Operation responses and group number for each operation in which the
attribute group occurs:
Specification of this attribute group (follow the style of IPP Model
Section 3):
Name of proposer:
Address of proposer:
Email address of proposer:

Note:  For attribute groups, the IPP Designated Expert will be the point
of contact for the approved registration specification, if any
maintenance of the registration specification is needed.

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12.9 Status code registration

Type of registration:  status code
Keyword symbolic name of this status code value:
Numeric value (to be assigned by the IPP Designated Expert in
consultation with IANA):
Operations that this status code may be used with:
Specification of this status code (follow the style of IPP Model Section
14 APPENDIX B:  Status Codes and Suggested Status Code Messages):
Name of proposer:
Address of proposer:
Email address of proposer:

Note:  For status codes, the Designated Expert will be the point of
contact for the approved registration specification, if any maintenance
of the registration specification is needed.


13. APPENDIX A: Terminology


This specification uses the terminology defined in this section.


13.1 Conformance Terminology


The key words "MUST", "MUST NOT", "REQUIRED", "SHOULD", "SHOULD NOT",
"RECOMMENDED", "MAY", and  "OPTIONAL" in this document are to be
interpreted as described in RFC 2119 [RFC2119].


13.1.1 NEED NOT

This term is not included in RFC 2119.  The verb "NEED NOT" indicates an
action that the subject of the sentence does not have to implement in
order to claim conformance to the standard.  The verb "NEED NOT" is used
instead of "MAY NOT" since "MAY NOT" sounds like a prohibition.


13.2 Model Terminology


13.2.1 Keyword

Keywords are used within this document as identifiers of semantic
entities within the abstract model (see section 4.1.2.3).  Attribute
names, some attribute values, attribute syntaxes, and attribute group
names are represented as keywords.


13.2.2 Attributes

An attribute is an item of information that is associated with an
instance of an IPP object.  An attribute consists of an attribute name
and one or more attribute values.  Each attribute has a specific


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attribute syntax.  All object attributes are defined in section 3.3.5
and all operation attributes are defined in section 3.

Job Template Attributes are described in section 4.2. The client
optionally supplies Job Template attributes in a create request
(operation requests that create Job objects).  The Printer object has
associated attributes which define supported and default values for the
Printer.


13.2.2.1 Attribute Name

Each attribute is uniquely identified in this document by its attribute
name.  An attribute name is a keyword.  The keyword attribute name is
given in the section header describing that attribute.  In running text
in this document, attribute names are indicated inside double quotation
marks (") where the quotation marks are not part of the keyword itself.


13.2.2.2 Attribute Group Name

Related attributes are grouped into named groups.  The name of the group
is a keyword.  The group name may be used in place of naming all the
attributes in the group explicitly.  Attribute groups are defined in
section 3.


13.2.2.3 Attribute Value

Each attribute has one or more values.  Attribute values are represented
in the syntax type specified for that attribute. In running text in this
document, attribute values are indicated inside single quotation marks
('), whether their attribute syntax is keyword, integer, text, etc.
where the quotation marks are not part of the value itself.


13.2.2.4 Attribute Syntax

Each attribute is defined using an explicit syntax type.  In this
document, each syntax type is defined as a keyword with specific
meaning.  The "Encoding and Transport" document [IPP-PRO] indicates the
actual "on-the-wire" encoding rules for each syntax type.  Attribute
syntax types are defined in section 4.1.


13.2.3 Supports

By definition, a Printer object supports an attribute only if that
Printer object responds with the corresponding attribute populated with
some value(s) in a response to a query for that attribute.  A Printer
object supports an attribute value if the value is one of the Printer
object's "supported values" attributes.  The device behind a Printer
object may exhibit a behavior that corresponds to some IPP attribute,
but if the Printer object, when queried for that attribute, doesn't
respond with the attribute, then as far as IPP is concerned, that
implementation does not support that feature. If the Printer object's


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"xxx-supported" attribute is not populated with a particular value (even
if that value is a legal value for that attribute), then that Printer
object does not support that particular value.

A conforming implementation MUST support all REQUIRED attributes.
However, even for REQUIRED attributes, conformance to IPP does not
mandate that all implementations support all possible values
representing all possible job processing behaviors and features.  For
example, if a given instance of a Printer supports only certain document
formats, then that Printer responds with the "document-format-supported"
attribute populated with a set of values, possibly only one, taken from
the entire set of possible values defined for that attribute. This
limited set of values represents the Printer's set of supported document
formats.  Supporting an attribute and some set of values for that
attribute enables IPP end users to be aware of and make use of those
features associated with that attribute and those values.  If an
implementation chooses to not support an attribute or some specific
value, then IPP end users would have no ability to make use of that
feature within the context of IPP itself.  However, due to existing
practice and legacy systems which are not IPP aware, there might be some
other mechanism outside the scope of IPP to control or request the
"unsupported" feature (such as embedded instructions within the document
data itself).

For example, consider the "finishings-supported" attribute.

  1) If a Printer object is not physically capable of stapling, the
     "finishings-supported" attribute MUST NOT be populated with the
     value of 'staple'.
  2) A Printer object is physically capable of stapling, however an
     implementation chooses not to support stapling in the IPP
     "finishings" attribute.  In this case, 'staple' MUST NOT be a value
     in the "finishings-supported" Printer object attribute. Without
     support for the value 'staple', an IPP end user would have no means
     within the protocol itself to request that a Job be stapled.
     However, an existing document data formatter might be able to
     request that the document be stapled directly with an embedded
     instruction within the document data.  In this case, the IPP
     implementation does not "support" stapling, however the end user is
     still able to have some control over the stapling of the completed
     job.
  3) A Printer object is physically capable of stapling, and an
     implementation chooses to support stapling in the IPP "finishings"
     attribute. In this case, 'staple' MUST be a value in the
     "finishings-supported" Printer object attribute. Doing so, would
     enable end users to be aware of and make use of the stapling
     feature using IPP attributes.


Even though support for Job Template attributes by a Printer object is
OPTIONAL, it is RECOMMENDED that if the device behind a Printer object
is capable of realizing any feature or function that corresponds to an
IPP attribute and some associated value, then that implementation SHOULD
support that IPP attribute and value.


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The set of values in any of the supported value attributes is set
(populated) by some administrative process or automatic sensing
mechanism that is outside the scope of this IPP/1.1 document.  For
administrative policy and control reasons, an administrator may choose
to make only a subset of possible values visible to the end user.  In
this case, the real output device behind the IPP Printer abstraction may
be capable of a certain feature, however an administrator is specifying
that access to that feature not be exposed to the end user through the
IPP protocol.  Also, since a Printer object may represent a logical
print device (not just a physical device) the actual process for
supporting a value is undefined and left up to the implementation.
However, if a Printer object supports a value, some manual human action
may be needed to realize the semantic action associated with the value,
but no end user action is required.

For example, if one of the values in the "finishings-supported"
attribute is 'staple', the actual process might be an automatic staple
action by a physical device controlled by some command sent to the
device.  Or, the actual process of stapling might be a manual action by
an operator at an operator attended Printer object.

For another example of how supported attributes function, consider a
system administrator who desires to control all print jobs so that no
job sheets are printed in order to conserve paper.  To force no job
sheets, the system administrator sets the only supported value for the
"job-sheets-supported" attribute to 'none'.  In this case, if a client
requests anything except 'none', the create request is rejected or the
"job-sheets" value is ignored (depending on the value of "ipp-attribute-
fidelity").  To force the use of job start/end sheets on all jobs, the
administrator does not include the value 'none' in the "job-sheets-
supported" attribute.  In this case, if a client requests 'none', the
create request is rejected or the "job-sheets" value is ignored (again
depending on the value of "ipp-attribute-fidelity").


13.2.4 print-stream page

A "print-stream page" is a page according to the definition of pages in
the language used to express the document data.


13.2.5 impression

An "impression" is the image (possibly many print-stream pages in
different configurations) imposed onto a single media page.



14. APPENDIX B:  Status Codes and Suggested Status Code Messages


This section defines status code enum keywords and values that are used
to provide semantic information on the results of an operation request.
Each operation response MUST include a status code.  The response MAY
also contain a status message that provides a short textual description
of the status.  The status code is intended for use by automata, and the

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status message is intended for the human end user.  Since the status
message is an OPTIONAL component of the operation response, an IPP
application (i.e., a browser, GUI, print driver or gateway) is NOT
REQUIRED to examine or display the status message, since it MAY not be
returned to the application.

The prefix of the status keyword defines the class of response as
follows:

  "informational" - Request received, continuing process
  "successful" - The action was successfully received, understood, and
     accepted
  "redirection" - Further action must be taken in order to complete the
     request
  "client-error" - The request contains bad syntax or cannot be
     fulfilled
  "server-error" - The IPP object  failed to fulfill an apparently
     valid request


As with type2 enums, IPP status codes are extensible.  IPP clients are
NOT REQUIRED to understand the meaning of all registered status codes,
though such understanding is obviously desirable.  However, IPP clients
MUST understand the class of any status code, as indicated by the
prefix, and treat any unrecognized response as being equivalent to the
first status code of that class, with the exception that an unrecognized
response MUST NOT be cached.  For example, if an unrecognized status
code of "client-error-xxx-yyy" is received by the client, it can safely
assume that there was something wrong with its request and treat the
response as if it had received a "client-error-bad-request" status code.
In such cases, IPP applications SHOULD present the OPTIONAL message (if
present) to the end user since the message is likely to contain human
readable information which will help to explain the unusual status.  The
name of the enum is the suggested status message for US English.

The status code values range from 0x0000 to 0x7FFF.  The value ranges
for each status code class are as follows:

  "successful" - 0x0000 to 0x00FF
  "informational" - 0x0100 to 0x01FF
  "redirection" - 0x0200 to 0x02FF
  "client-error" - 0x0400 to 0x04FF
  "server-error" - 0x0500 to 0x05FF


The top half (128 values) of each range (0x0n40 to 0x0nFF, for n = 0 to
5) is reserved for private use within each status code class.  Values
0x0600 to 0x7FFF are reserved for future assignment and MUST NOT be
used.


14.1 Status Codes


Each status code is described below. Section 14.1.5.9 contains a table
that indicates which status codes apply to which operations.  The
Implementer's Guide [IPP-IIG] describe the suggested steps for

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processing IPP attributes for all operations, including returning status
codes.


14.1.1 Informational

This class of status code indicates a provisional response and is to be
used for informational purposes only.

There are no status codes defined in IPP/1.1 for this class of status
code.


14.1.2 Successful Status Codes

This class of status code indicates that the client's request was
successfully received, understood, and accepted.


14.1.2.1 successful-ok (0x0000)

The request has succeeded and no request attributes were substituted or
ignored.  In the case of a response to a create request, the
'successful-ok' status code indicates that the request was successfully
received and validated, and that the Job object has been created; it
does not indicate that the job has been processed.  The transition of
the Job object into the 'completed' state is the only indicator that the
job has been printed.


14.1.2.2 successful-ok-ignored-or-substituted-attributes (0x0001)

The request has succeeded, but some supplied (1) attributes were ignored
or (2) unsupported values were substituted with supported values or were
ignored in order to perform the operation without rejecting it.
Unsupported attributes, attribute syntaxes, or values MUST be returned
in the Unsupported Attributes group of the response for all operations.
There is an exception to this rule for the query operations:  Get-
Printer-Attributes, Get-Jobs, and Get-Job-Attributes for the "requested-
attributes" operation attribute only.  When the supplied values of the
"requested-attributes" operation attribute are requesting attributes
that are not supported, the IPP object MAY, but is NOT REQUIRED to,
return the "requested-attributes" attribute in the Unsupported Attribute
response group (with the unsupported values only).  See section 3.2.1.2.


14.1.2.3 successful-ok-conflicting-attributes (0x0002)

The request has succeeded, but some supplied attribute values conflicted
with the values of other supplied attributes.  These conflicting values
were either (1) substituted with (supported) values or (2) the
attributes were removed in order to process the job without rejecting
it.  Attributes or values which conflict with other attributes and have
been substituted or ignored MUST be returned in the Unsupported
Attributes group of the response for all operations as supplied by the
client.  See section 3.2.1.2.


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14.1.3 Redirection Status Codes

This class of status code indicates that further action needs to be
taken to fulfill the request.

There are no status codes defined in IPP/1.1 for this class of status
code.


14.1.4 Client Error Status Codes

This class of status code is intended for cases in which the client
seems to have erred.  The IPP object SHOULD return a message containing
an explanation of the error situation and whether it is a temporary or
permanent condition.


14.1.4.1 client-error-bad-request (0x0400)

The request could not be understood by the IPP object due to malformed
syntax (such as the value of a fixed length attribute whose length does
not match the prescribed length for that attribute - see the
Implementer's Guide [IPP-IIG] ).  The IPP application SHOULD NOT repeat
the request without modifications.


14.1.4.2 client-error-forbidden (0x0401)

The IPP object understood the request, but is refusing to fulfill it.
Additional authentication information or authorization credentials will
not help and the request SHOULD NOT be repeated.  This status code is
commonly used when the IPP object does not wish to reveal exactly why
the request has been refused or when no other response is applicable.


14.1.4.3 client-error-not-authenticated (0x0402)

The request requires user authentication.  The IPP client may repeat the
request with suitable authentication information. If the request already
included authentication information, then this status code indicates
that authorization has been refused for those credentials.  If this
response contains the same challenge as the prior response, and the user
agent has already attempted authentication at least once, then the
response message may contain relevant diagnostic information.  This
status codes reveals more information than "client-error-forbidden".


14.1.4.4 client-error-not-authorized (0x0403)

The requester is not authorized to perform the request.  Additional
authentication information or authorization credentials will not help
and the request SHOULD NOT be repeated.  This status code is used when
the IPP object wishes to reveal that the authentication information is
understandable, however, the requester is explicitly not authorized to
perform the request.  This status codes reveals more information than
"client-error-forbidden" and "client-error-not-authenticated".


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14.1.4.5 client-error-not-possible (0x0404)

This status code is used when the request is for something that can not
happen.  For example, there might be a request to cancel a job that has
already been canceled or aborted by the system.  The IPP client SHOULD
NOT repeat the request.


14.1.4.6 client-error-timeout (0x0405)

The client did not produce a request within the time that the IPP object
was prepared to wait.  For example, a client issued a Create-Job
operation and then, after a long period of time, issued a Send-Document
operation and this error status code was returned in response to the
Send-Document request  (see section 3.3.1).  The IPP object might have
been forced to clean up resources that had been held for the waiting
additional Documents.  The IPP object was forced to close the Job since
the client took too long.  The client SHOULD NOT repeat the request
without modifications.


14.1.4.7 client-error-not-found (0x0406)

The IPP object has not found anything matching the request URI.  No
indication is given of whether the condition is temporary or permanent.
For example, a client with an old reference to a Job (a URI) tries to
cancel the Job, however in the mean time the Job might have been
completed and all record of it at the Printer has been deleted.  This
status code, 'client-error-not-found' is returned indicating that the
referenced Job can not be found.  This error status code is also used
when a client supplies a URI as a reference to the document data in
either a Print-URI or Send-URI operation, but the document can not be
found.

In practice, an IPP application should avoid a not found situation by
first querying and presenting a list of valid Printer URIs and Job URIs
to the end-user.


14.1.4.8 client-error-gone (0x0407)

The requested object is no longer available and no forwarding address is
known.  This condition should be considered permanent.  Clients with
link editing capabilities should delete references to the request URI
after user approval.  If the IPP object does not know or has no facility
to determine, whether or not the condition is permanent, the status code
"client-error-not-found" should be used instead.

This response is primarily intended to assist the task of maintenance by
notifying the recipient that the resource is intentionally unavailable
and that the IPP object administrator desires that remote links to that
resource be removed. It is not necessary to mark all permanently
unavailable resources as "gone" or to keep the mark for any length of
time -- that is left to the discretion of the IPP object administrator.



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14.1.4.9 client-error-request-entity-too-large (0x0408)

The IPP object is refusing to process a request because the request
entity is larger than the IPP object is willing or able to process.  An
IPP Printer returns this status code when it limits the size of print
jobs and it receives a print job that exceeds that limit or when the
attributes are so many that their encoding causes the request entity to
exceed IPP object capacity.


14.1.4.10 client-error-request-value-too-long (0x0409)

The IPP object is refusing to service the request because one or more of
the client-supplied attributes has a variable length value that is
longer than the maximum length specified for that attribute.  The IPP
object might not have sufficient resources (memory, buffers, etc.) to
process (even temporarily), interpret, and/or ignore a value larger than
the maximum length.  Another use of this error code is when the IPP
object supports the processing of a large value that is less than the
maximum length, but during the processing of the request as a whole, the
object may pass the value onto some other system component which is not
able to accept the large value.  For more details, see the Implementer's
Guide [IPP-IIG] .

Note:  For attribute values that are URIs, this rare condition is only
likely to occur when a client has improperly submitted a request with
long query information (e.g. an IPP application allows an end-user to
enter an invalid URI), when the client has descended into a URI "black
hole" of redirection (e.g., a redirected URI prefix that points to a
suffix of itself), or when the IPP object is under attack by a client
attempting to exploit security holes present in some IPP objects using
fixed-length buffers for reading or manipulating the Request-URI.


14.1.4.11 client-error-document-format-not-supported (0x040A)

The IPP object is refusing to service the request because the document
data is in a format, as specified in the "document-format" operation
attribute, that is not supported by the Printer object.  This error is
returned independent of the client-supplied "ipp-attribute-fidelity".
The Printer object MUST return this status code, even if there are other
attributes that are not supported as well, since this error is a bigger
problem than with Job Template attributes.


14.1.4.12 client-error-attributes-or-values-not-supported (0x040B)

In a create request, if the Printer object does not support one or more
attributes, attribute syntaxes, or attribute values supplied in the
request and the client supplied the "ipp-attributes-fidelity" operation
attribute with the 'true' value, the Printer object MUST return this
status code.  For example, if the request indicates 'iso-a4' media, but
that media type is not supported by the Printer object.  Or, if the
client supplies an optional attribute and the attribute itself is not
even supported by the Printer.  If the "ipp-attribute-fidelity"


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attribute is 'false', the Printer MUST ignore or substitute values for
unsupported attributes and values rather than reject the request and
return this status code.

For any operation where a client requests attributes (such as a Get-
Jobs, Get-Printer-Attributes, or Get-Job-Attributes operation), if the
IPP object does not support one or more of the requested attributes, the
IPP object simply ignores the unsupported requested attributes and
processes the request as if they had not been supplied, rather than
returning this status code.  In this case, the IPP object MUST return
the 'successful-ok-ignored-or-substituted-attributes' status code and
MAY return the unsupported attributes as values of the "requested-
attributes" in the Unsupported Attributes Group (see section 14.1.2.2).


14.1.4.13 client-error-uri-scheme-not-supported (0x040C)

The type of the client supplied URI in a Print-URI or a Send-URI
operation is not supported.


14.1.4.14 client-error-charset-not-supported (0x040D)

For any operation, if the IPP Printer does not support the charset
supplied by the client in the "attributes-charset" operation attribute,
the Printer MUST reject the operation and return this status and any
'text' or 'name' attributes using the 'utf-8' charset (see Section
3.1.4.1).


14.1.4.15 client-error-conflicting-attributes (0x040E)

The request is rejected because some attribute values conflicted with
the values of other attributes which this specification does not permit
to be substituted or ignored.


14.1.5 Server Error Status Codes

This class of status codes indicates cases in which the IPP object is
aware that it has erred or is incapable of performing the request.  The
IPP object SHOULD include a message containing an explanation of the
error situation, and whether it is a temporary or permanent condition.


14.1.5.1 server-error-internal-error (0x0500)

The IPP object encountered an unexpected condition that prevented it
from fulfilling the request.  This error status code differs from
"server-error-temporary-error" in that it implies a more permanent type
of internal error.  It also differs from "server-error-device-error" in
that it implies an unexpected condition (unlike a paper-jam or out-of-
toner problem which is undesirable but expected).  This error status
code indicates that probably some knowledgeable human intervention is
required.



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14.1.5.2 server-error-operation-not-supported (0x0501)

The IPP object does not support the functionality required to fulfill
the request. This is the appropriate response when the IPP object does
not recognize an operation or is not capable of supporting it.


14.1.5.3 server-error-service-unavailable (0x0502)

The IPP object is currently unable to handle the request due to a
temporary overloading or maintenance of the IPP object.  The implication
is that this is a temporary condition which will be alleviated after
some delay. If known, the length of the delay may be indicated in the
message.  If no delay is given, the IPP application should handle the
response as it would for a "server-error-temporary-error" response.  If
the condition is more permanent, the error status codes "client-error-
gone" or "client-error-not-found" could be used.


14.1.5.4 server-error-version-not-supported (0x0503)

The IPP object does not support, or refuses to support, the IPP protocol
version that was used in the request message.  The IPP object is
indicating that it is unable or unwilling to complete the request using
the same version as supplied in the request other than with this error
message. The response should contain a Message describing why that
version is not supported and what other versions are supported by that
IPP object.

A conforming IPP/1.1 client MUST specify a valid version ('1.1' or
'1.0') on each request.  A conforming IPP/1.1 object MUST NOT return
this status code to a conforming IPP/1.1 or IPP/1.0 client.  An IPP
object MUST return this status code to a non-conforming IPP client.  The
response MUST identify in the "version-number" operation attribute the
closest version number that the IPP object does support.  For example,
if a client supplies version '1.0', a conforming IPP/1.1 object MUST
respond with version '1.0'.


14.1.5.5 server-error-device-error (0x0504)

A printer error, such as a paper jam, occurs while the IPP object
processes a Print or Send operation.  The response contains the true Job
Status (the values of the "job-state" and "job-state-reasons"
attributes).  Additional information can be returned in the optional
"job-state-message" attribute value or in the OPTIONAL status message
that describes the error in more detail.  This error status code is only
returned in situations where the Printer is unable to accept the create
request because of such a device error.  For example, if the Printer is
unable to spool, and can only accept one job at a time, the reason it
might reject a create request is that the printer currently has a paper
jam.  In many cases however, where the Printer object can accept the
request even though the Printer has some error condition, the
'successful-ok' status code will be returned.  In such a case, the



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client would look at the returned Job Object Attributes or later query
the Printer to determine its state and state reasons.


14.1.5.6 server-error-temporary-error (0x0505)

A temporary error such as a buffer full write error, a memory overflow
(i.e. the document data exceeds the memory of the Printer), or a disk
full condition, occurs while the IPP Printer processes an operation.
The client MAY try the unmodified request again at some later point in
time with an expectation that the temporary internal error condition may
have been cleared.  Alternatively, as an implementation option, a
Printer object MAY delay the response until the temporary condition is
cleared so that no error is returned.


14.1.5.7 server-error-not-accepting-jobs (0x0506)

A temporary error indicating that the Printer is not currently accepting
jobs, because the administrator has set the value of the Printer's
"printer-is-not-accepting-jobs" attribute to 'false' (by means outside
the scope of this IPP/1.1 document).


14.1.5.8 server-error-busy (0x0507)

A temporary error indicating that the Printer is too busy processing
jobs and/or other requests. The client SHOULD try the unmodified request
again at some later point in time with an expectation that the temporary
busy condition will have been cleared.


14.1.5.9 server-error-job-canceled (0x0508)

An error indicating that the job has been canceled by an operator or the
system while the client was transmitting the data to the IPP Printer.
If a job-id and job-uri had been created, then they are returned in the
Print-Job, Send-Document, or Send-URI response as usual; otherwise, no
job-id and job-uri are returned in the response.


















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14.2 Status Codes for IPP Operations

PJ = Print-Job, PU = Print-URI, CJ = Create-Job, SD = Send-Document
SU = Send-URI, V = Validate-Job, GA = Get-Job-Attributes and
Get-Printer-Attributes, GJ = Get-Jobs, C = Cancel-Job

                                               IPP Operations
IPP Status Keyword                       PJ PU CJ SD SU V GA GJ C
------------------                       -- -- -- -- -- - -- -- -
successful-ok                            x  x  x  x  x  x x  x  x
successful-ok-ignored-or-substituted-    x  x  x  x  x  x x  x  x
     attributes
successful-ok-conflicting-attributes     x  x  x  x  x  x x  x  x
client-error-bad-request                 x  x  x  x  x  x x  x  x
client-error-forbidden                   x  x  x  x  x  x x  x  x
client-error-not-authenticated           x  x  x  x  x  x x  x  x
client-error-not-authorized              x  x  x  x  x  x x  x  x
client-error-not-possible                x  x  x  x  x  x x  x  x
client-error-timeout                              x  x
client-error-not-found                   x  x  x  x  x  x x  x  x
client-error-gone                        x  x  x  x  x  x x  x  x
client-error-request-entity-too-large    x  x  x  x  x  x x  x  x
client-error-request-value-too-long      x  x  x  x  x  x x  x  x
client-error-document-format-not-        x  x     x  x  x x
     supported
client-error-attributes-or-values-not-   x  x  x  x  x  x x  x  x
     supported
client-error-uri-scheme-not-supported       x        x
client-error-charset-not-supported       x  x  x  x  x  x x  x  x
client-error-conflicting-attributes      x  x  x  x  x  x x  x  x
server-error-internal-error              x  x  x  x  x  x x  x  x
server-error-operation-not-supported        x  x  x  x
server-error-service-unavailable         x  x  x  x  x  x x  x  x
server-error-version-not-supported       x  x  x  x  x  x x  x  x
server-error-device-error                x  x  x  x  x
server-error-temporary-error             x  x  x  x  x
server-error-not-accepting-jobs          x  x  x        x
server-error-busy                        x  x  x  x  x  x x  x  x
server-error-job-canceled                x        x
















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HJ = Hold-Job, RJ = Release-Job, RS = Restart-Job
PP = Pause-Printer, RP = Resume-Printer, PJ = Purge-Jobs

                                         IPP Operations (cont.)
IPP Status Keyword                       HJ RJ RS PP RP PJ
------------------                       -- -- -- -- -- --
successful-ok                            x  x  x  x  x  x
successful-ok-ignored-or-substituted-    x  x  x  x  x  x
     attributes
successful-ok-conflicting-attributes     x  x  x  x  x  x
client-error-bad-request                 x  x  x  x  x  x
client-error-forbidden                   x  x  x  x  x  x
client-error-not-authenticated           x  x  x  x  x  x
client-error-not-authorized              x  x  x  x  x  x
client-error-not-possible                x  x  x  x  x  x
client-error-timeout
client-error-not-found                   x  x  x  x  x  x
client-error-gone                        x  x  x  x  x  x
client-error-request-entity-too-large    x  x  x  x  x  x
client-error-request-value-too-long      x  x  x  x  x  x
client-error-document-format-not-
     supported
client-error-attributes-or-values-not-   x  x  x  x  x  x
     supported
client-error-uri-scheme-not-supported
client-error-charset-not-supported       x  x  x  x  x  x
client-error-conflicting-attributes      x  x  x  x  x  x
server-error-internal-error              x  x  x  x  x  x
server-error-operation-not-supported     x  x  x  x  x  x
server-error-service-unavailable         x  x  x  x  x  x
server-error-version-not-supported       x  x  x  x  x  x
server-error-device-error
server-error-temporary-error
server-error-not-accepting-jobs
server-error-busy                        x  x  x  x  x  x
server-error-job-canceled



















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15. APPENDIX C:  "media" keyword values


Standard keyword values are taken from several sources.

Standard values are defined (taken from DPA[ISO10175] and the Printer
MIB[RFC1759]):

  'default': The default medium for the output device
  'iso-a4-white': Specifies the ISO A4 white medium
  'iso-a4-colored': Specifies the ISO A4 colored medium
  'iso-a4-transparent' Specifies the ISO A4 transparent medium
  'iso-a3-white': Specifies the ISO A3 white medium
  'iso-a3-colored': Specifies the ISO A3 colored medium
  'iso-a5-white': Specifies the ISO A5 white medium
  'iso-a5-colored': Specifies the ISO A5 colored medium
  'iso-b4-white': Specifies the ISO B4 white medium
  'iso-b4-colored': Specifies the ISO B4 colored medium
  'iso-b5-white': Specifies the ISO B5 white medium
  'iso-b5-colored': Specifies the ISO B5 colored medium
  'jis-b4-white': Specifies the JIS B4 white medium
  'jis-b4-colored': Specifies the JIS B4 colored medium
  'jis-b5-white': Specifies the JIS B5 white medium
  'jis-b5-colored': Specifies the JIS B5 colored medium


The following standard values are defined for North American media:

  'na-letter-white': Specifies the North American letter white medium
  'na-letter-colored': Specifies the North American letter colored
     medium
  'na-letter-transparent': Specifies the North American letter
     transparent medium
  'na-legal-white': Specifies the North American legal white medium
  'na-legal-colored': Specifies the North American legal colored medium


The following standard values are defined for envelopes:

  'iso-b4-envelope': Specifies the ISO B4 envelope medium
  'iso-b5-envelope': Specifies the ISO B5 envelope medium
  'iso-c3-envelope': Specifies the ISO C3 envelope medium
  'iso-c4-envelope': Specifies the ISO C4 envelope medium
  'iso-c5-envelope': Specifies the ISO C5 envelope medium
  'iso-c6-envelope': Specifies the ISO C6 envelope medium
  'iso-designated-long-envelope': Specifies the ISO Designated Long
     envelope medium
  'na-10x13-envelope': Specifies the North American 10x13 envelope
     medium
  'na-9x12-envelope': Specifies the North American 9x12 envelope medium
  'monarch-envelope': Specifies the Monarch envelope
  'na-number-10-envelope': Specifies the North American number 10
     business envelope medium

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  'na-7x9-envelope': Specifies the North American 7x9 inch envelope
  'na-9x11-envelope': Specifies the North American 9x11 inch envelope
  'na-10x14-envelope': Specifies the North American 10x14 inch envelope
  'na-number-9-envelope': Specifies the North American number 9
     business envelope
  'na-6x9-envelope': Specifies the North American 6x9 inch envelope
  'na-10x15-envelope': Specifies the North American 10x15 inch envelope


The following standard values are defined for the less commonly used
media (white-only):

  'executive-white': Specifies the white executive medium
  'folio-white': Specifies the folio white medium
  'invoice-white': Specifies the white invoice medium
  'ledger-white': Specifies the white ledger medium
  'quarto-white': Specified the white quarto medium
  'iso-a0-white': Specifies the ISO A0 white medium
  'iso-a1-white': Specifies the ISO A1 white medium
  'iso-a2-white': Specifies the ISO A2 white medium
  'iso-a6-white': Specifies the ISO A6 white medium
  'iso-a7-white': Specifies the ISO A7 white medium
  'iso-a8-white': Specifies the ISO A8 white medium
  'iso-a9-white': Specifies the ISO A9 white medium
  'iso-10-white': Specifies the ISO A10 white medium
  'iso-b0-white': Specifies the ISO B0 white medium
  'iso-b1-white': Specifies the ISO B1 white medium
  'iso-b2-white': Specifies the ISO B2 white medium
  'iso-b3-white': Specifies the ISO B3 white medium
  'iso-b6-white': Specifies the ISO B6 white medium
  'iso-b7-white': Specifies the ISO B7 white medium
  'iso-b8-white': Specifies the ISO B8 white medium
  'iso-b9-white': Specifies the ISO B9 white medium
  'iso-b10-white': Specifies the ISO B10 white medium
  'jis-b0-white': Specifies the JIS B0 white medium
  'jis-b1-white': Specifies the JIS B1 white medium
  'jis-b2-white': Specifies the JIS B2 white medium
  'jis-b3-white': Specifies the JIS B3 white medium
  'jis-b6-white': Specifies the JIS B6 white medium
  'jis-b7-white': Specifies the JIS B7 white medium
  'jis-b8-white': Specifies the JIS B8 white medium
  'jis-b9-white': Specifies the JIS B9 white medium
  'jis-b10-white': Specifies the JIS B10 white medium


The following standard values are defined for engineering media:

  'a': Specifies the engineering A size medium
  'b': Specifies the engineering B size medium
  'c': Specifies the engineering C size medium
  'd': Specifies the engineering D size medium
  'e': Specifies the engineering E size medium




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The following standard values are defined for input-trays (from ISO DPA
and the Printer MIB):

  'top': The top input tray in the printer.
  'middle': The middle input tray in the printer.
  'bottom': The bottom input tray in the printer.
  'envelope': The envelope input tray in the printer.
  'manual': The manual feed input tray in the printer.
  'large-capacity': The large capacity input tray in the printer.
  'main': The main input tray
  'side': The side input tray


The following standard values are defined for media sizes (from ISO
DPA):

  'iso-a0': Specifies the ISO A0 size: 841 mm by 1189 mm as defined in
     ISO 216
  'iso-a1': Specifies the ISO A1 size: 594 mm by 841 mm as defined in
     ISO 216
  'iso-a2': Specifies the ISO A2 size: 420 mm by 594 mm as defined in
     ISO 216
  'iso-a3': Specifies the ISO A3 size: 297 mm by 420 mm as defined in
     ISO 216
  'iso-a4': Specifies the ISO A4 size: 210 mm by 297 mm as defined in
     ISO 216
  'iso-a5': Specifies the ISO A5 size: 148 mm by 210 mm as defined in
     ISO 216
  'iso-a6': Specifies the ISO A6 size: 105 mm by 148 mm as defined in
     ISO 216
  'iso-a7': Specifies the ISO A7 size: 74 mm by 105 mm as defined in
     ISO 216
  'iso-a8': Specifies the ISO A8 size: 52 mm by 74 mm as defined in ISO
     216
  'iso-a9': Specifies the ISO A9 size: 37 mm by 52 mm as defined in ISO
     216
  'iso-a10': Specifies the ISO A10 size: 26 mm by 37 mm as defined in
     ISO 216
  'iso-b0': Specifies the ISO B0 size: 1000 mm by 1414 mm as defined in
     ISO 216
  'iso-b1': Specifies the ISO B1 size: 707 mm by 1000 mm as defined in
     ISO 216
  'iso-b2': Specifies the ISO B2 size: 500 mm by 707 mm as defined in
     ISO 216
  'iso-b3': Specifies the ISO B3 size: 353 mm by 500 mm as defined in
     ISO 216
  'iso-b4': Specifies the ISO B4 size: 250 mm by 353 mm as defined in
     ISO 216
  'iso-b5': Specifies the ISO B5 size: 176 mm by 250 mm as defined in
     ISO 216
  'iso-b6': Specifies the ISO B6 size: 125 mm by 176 mm as defined in
     ISO 216
  'iso-b7': Specifies the ISO B7 size: 88 mm by 125 mm as defined in
     ISO 216


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  'iso-b8': Specifies the ISO B8 size: 62 mm by 88 mm as defined in ISO
     216
  'iso-b9': Specifies the ISO B9 size: 44 mm by 62 mm as defined in ISO
     216
  'iso-b10': Specifies the ISO B10 size: 31 mm by 44 mm as defined in
     ISO 216
  'na-letter': Specifies the North American letter size: 8.5 inches by
     11 inches
  'na-legal': Specifies the North American legal size: 8.5 inches by 14
     inches
  'executive': Specifies the executive size (7.25 X 10.5 in)
  'folio': Specifies the folio size (8.5 X 13 in)
  'invoice': Specifies the invoice size (5.5 X 8.5 in)
  'ledger': Specifies the ledger size (11 X 17 in)
  'quarto': Specifies the quarto size (8.5 X 10.83 in)
  'iso-c3': Specifies the ISO C3 size: 324 mm by 458 mm as defined in
     ISO 269
  'iso-c4': Specifies the ISO C4 size: 229 mm by 324 mm as defined in
     ISO 269
  'iso-c5': Specifies the ISO C5 size: 162 mm by 229 mm as defined in
     ISO 269
  'iso-c6': Specifies the ISO C6 size: 114 mm by 162 mm as defined in
     ISO 269
  'iso-designated-long': Specifies the ISO Designated Long size: 110 mm
     by 220 mm as defined in ISO 269
  'na-10x13-envelope': Specifies the North American 10x13 size: 10
     inches by 13 inches
  'na-9x12-envelope': Specifies the North American 9x12 size: 9 inches
     by 12 inches
  'na-number-10-envelope': Specifies the North American number 10
     business envelope size: 4.125 inches by 9.5 inches
  'na-7x9-envelope': Specifies the North American 7x9 inch envelope
     size
  'na-9x11-envelope': Specifies the North American 9x11 inch envelope
     size
  'na-10x14-envelope': Specifies the North American 10x14 inch envelope
     size
  'na-number-9-envelope': Specifies the North American number 9
     business envelope size
  'na-6x9-envelope': Specifies the North American 6x9 envelope size
  'na-10x15-envelope': Specifies the North American 10x15 envelope size
  'monarch-envelope': Specifies the Monarch envelope size (3.87 x 7.5
     in)
  'jis-b0': Specifies the JIS B0 size: 1030mm x 1456mm
  'jis-b1': Specifies the JIS B1 size: 728mm x 1030mm
  'jis-b2': Specifies the JIS B2 size: 515mm x 728mm
  'jis-b3': Specifies the JIS B3 size: 364mm x 515mm
  'jis-b4': Specifies the JIS B4 size: 257mm x 364mm
  'jis-b5': Specifies the JIS B5 size: 182mm x 257mm
  'jis-b6': Specifies the JIS B6 size: 128mm x 182mm
  'jis-b7': Specifies the JIS B7 size: 91mm x 128mm
  'jis-b8': Specifies the JIS B8 size: 64mm x 91mm
  'jis-b9': Specifies the JIS B9 size: 45mm x 64mm
  'jis-b10': Specifies the JIS B10 size: 32mm x 45mm

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16. APPENDIX D: Processing IPP Attributes


When submitting a print job to a Printer object, the IPP model allows a
client to supply operation and Job Template attributes along with the
document data.  These Job Template attributes in the create request
affect the rendering, production and finishing of the documents in the
job.  Similar types of instructions may also be contained in the
document to be printed, that is, embedded within the print data itself.
In addition, the Printer has a set of attributes that describe what
rendering and finishing options which are supported by that Printer.
This model, which allows for flexibility and power, also introduces the
potential that at job submission time, these client-supplied attributes
may conflict with either:

  - what the implementation is capable of realizing (i.e., what the
     Printer supports), as well as
  - the instructions embedded within the print data itself.


The following sections describe how these two types of conflicts are
handled in the IPP model.


16.1 Fidelity


If there is a conflict between what the client requests and what a
Printer object supports, the client may request one of two possible
conflict handling mechanisms:

  1) either reject the job since the job can not be processed exactly
     as specified, or
  2) allow the Printer to make any changes necessary to proceed with
     processing the Job the best it can.


In the first case the client is indicating to the Printer object: "Print
the job exactly as specified with no exceptions, and if that can't be
done, don't even bother printing the job at all." In the second case,
the client is indicating to the Printer object: "It is more important to
make sure the job is printed rather than be processed exactly as
specified; just make sure the job is printed even if client supplied
attributes need to be changed or ignored."

The IPP model accounts for this situation by introducing an "ipp-
attribute-fidelity" attribute.

In a create request, "ipp-attribute-fidelity" is a boolean operation
attribute that is OPTIONALLY supplied by the client.  The value 'true'
indicates that total fidelity to client supplied Job Template attributes
and values is required.  The client is requesting that the Job be
printed exactly as specified, and if that is not possible then the job
MUST be rejected rather than processed incorrectly.  The value 'false'
indicates that a reasonable attempt to print the Job is acceptable.  If
a Printer does not support some of the client supplied Job Template
attributes or values, the Printer MUST ignore them or substitute any


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supported value for unsupported values, respectively.  The Printer may
choose to substitute the default value associated with that attribute,
or use some other supported value that is similar to the unsupported
requested value.  For example, if a client supplies a "media" value of
'na-letter', the Printer may choose to substitute 'iso-a4' rather than a
default value of 'envelope'. If the client does not supply the "ipp-
attribute-fidelity" attribute, the Printer assumes a value of 'false'.

Each Printer implementation MUST support both types of "fidelity"
printing (that is whether the client supplies a value of 'true' or
'false'):

  - If the client supplies 'false' or does not supply the attribute,
     the Printer object MUST always accept the request by ignoring
     unsupported Job Template attributes and by substituting unsupported
     values of supported Job Template attributes with supported values.
  - If the client supplies 'true', the Printer object MUST reject the
     request if the client supplies unsupported Job Template attributes.


Since a client can always query a Printer to find out exactly what is
and is not supported, "ipp-attribute-fidelity" set to 'false' is useful
when:

  1) The End-User uses a command line interface to request attributes
     that might not be supported.
  2) In a GUI context, if the End User expects the job might be moved
     to another printer and prefers a sub-optimal result to nothing at
     all.
  3) The End User just wants something reasonable in lieu of nothing at
     all.


16.2 Page Description Language (PDL) Override


If there is a conflict between the value of an IPP Job Template
attribute and a corresponding instruction in the document data, the
value of the IPP attribute SHOULD take precedence over the document
instruction.  Consider the case where a previously formatted file of
document data is sent to an IPP Printer.  In this case, if the client
supplies any attributes at job submission time, the client desires that
those attributes override the embedded instructions.  Consider the case
were a previously formatted document has embedded in it commands to load
'iso-a4' media.  However, the document is passed to an end user that
only has access to a printer with 'na-letter' media loaded.  That end
user most likely wants to submit that document to an IPP Printer with
the "media" Job Template attribute set to 'na-letter'.  The job
submission attribute should take precedence over the embedded PDL
instruction.  However, until companies that supply document data
interpreters allow a way for external IPP attributes to take precedence
over embedded job production instructions, a Printer might not be able
to support the semantics that IPP attributes override the embedded
instructions.



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The IPP model accounts for this situation by introducing a "pdl-
override-supported" attribute that describes the Printer objects
capabilities to override instructions embedded in the PDL data stream.
The value of the "pdl-override-supported" attribute is configured by
means outside the scope of this IPP/1.1 document.

This REQUIRED Printer attribute takes on the following values:

  - 'attempted': This value indicates that the Printer object attempts
     to make the IPP attribute values take precedence over embedded
     instructions in the document data, however there is no guarantee.
  - 'not-attempted': This value indicates that the Printer object makes
     no attempt to make the IPP attribute values take precedence over
     embedded instructions in the document data.


At job processing time, an implementation that supports the value of
'attempted' might do one of several different actions:

  1) Generate an output device specific command sequence to realize the
     feature represented by the IPP attribute value.
  2) Parse the document data itself and replace the conflicting
     embedded instruction with a new embedded instruction that matches
     the intent of the IPP attribute value.
  3) Indicate to the Printer that external supplied attributes take
     precedence over embedded instructions and then pass the external
     IPP attribute values to the document data interpreter.
  4) Anything else that allows for the semantics that IPP attributes
     override embedded document data instructions.


Since 'attempted' does not offer any type of guarantee, even though a
given Printer object might not do a very "good" job of attempting to
ensure that IPP attributes take a higher precedence over instructions
embedded in the document data, it would still be a conforming
implementation.

At job processing time, an implementation that supports the value of
'not-attempted' might do one of the following actions:

  1) Simply pre-pend the document data with the PDL instruction that
     corresponds to the client-supplied PDL attribute, such that if the
     document data also has the same PDL instruction, it will override
     what the Printer object pre-pended.  In other words, this
     implementation is using the same implementation semantics for the
     client-supplied IPP attributes as for the Printer object defaults.
  2) Parse the document data and replace the conflicting embedded
     instruction with a new embedded instruction that approximates, but
     does not match, the semantic intent of the IPP attribute value.


Note:  The "ipp-attribute-fidelity" attribute applies to the Printer's
ability to either accept or reject other unsupported Job Template
attributes.  In other words, if "ipp-attribute-fidelity" is set to
'true', a Job is accepted if and only if the client supplied Job
Template attributes and values are supported by the Printer.  Whether
these attributes actually affect the processing of the Job when the

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document data contains embedded instructions depends on the ability of
the Printer to override the instructions embedded in the document data
with the semantics of the IPP attributes.  If the document data
attributes can be overridden ("pdl-override-supported" set to
'attempted'), the Printer makes an attempt to use the IPP attributes
when processing the Job. If the document data attributes can not be
overridden ("pdl-override-supported" set to 'not-attempted'), the
Printer makes no attempt to override the embedded document data
instructions with the IPP attributes when processing the Job, and hence,
the IPP attributes may fail to affect the Job processing and output when
the corresponding instruction is embedded in the document data.


16.3 Using Job Template Attributes During Document Processing.


The Printer object uses some of the Job object's Job Template attributes
during the processing of the document data associated with that job.
These include, but are not limited to, "orientation-requested", "number-
up", "sides", "media", and "copies".  The processing of each document in
a Job Object MUST follow the steps below. These steps are intended only
to identify when and how attributes are to be used in processing
document data and any alternative steps that accomplishes the same
effect can be used to implement this specification.

  1. Using the client supplied "document-format" attribute or some form
     of document format detection algorithm (if the value of "document-
     format" is not specific enough), determine whether or not the
     document data has already been formatted for printing. If the
     document data has been formatted, then go to step 2. Otherwise, the
     document data MUST be formatted. The formatting detection algorithm
     is implementation defined and is not specified by this
     specification. The formatting of the document data uses the
     "orientation-requested" attribute to determine how the formatted
     print data should be placed on a print-stream page, see section
     4.2.10 for the details.

  2. The document data is in the form of a print-stream in a known
     media type. The "page-ranges" attribute is used to select, as
     specified in section 4.2.7, a sub-sequence of the pages in the
     print-stream that are to be processed and images.

  3. The input to this step is a sequence of print-stream pages. This
     step is controlled by the "number-up" attribute. If the value of
     "number-up" is N, then during the processing of the print-stream
     pages, each N print-stream pages are positioned, as specified in
     section 4.2.9, to create a single impression. If a given document
     does not have N more print-stream pages, then the completion of the
     impression is controlled by the "multiple-document-handling"
     attribute as described in section 4.2.4; when the value of this
     attribute is 'single-document' or 'single-document-new-sheet', the
     print-stream pages of document data from subsequent documents is
     used to complete the impression.




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     The size(scaling), position(translation) and rotation of the print-
     stream pages on the impression is implementation defined.  Note
     that during this process the print-stream pages may be rendered to
     a form suitable for placing on the impression; this rendering is
     controlled by the values of the "printer-resolution" and "print-
     quality" attributes as described in sections 4.2.12 and 4.2.13. In
     the case N=1, the impression is nearly the same as the print-stream
     page; the differences would only be in the size, position and
     rotation of the print-stream page and/or any decoration, such as a
     frame to the page, that is added by the implementation.

  4. The collection of impressions is placed, in sequence, onto sides
     of the media sheets. This placement is controlled by the "sides"
     attribute and the orientation of the print-stream page, as
     described in section 4.2.8. The orientation of the print-stream
     pages affects the orientation of the impression; for example, if
     "number-up" equals 2, then, typically, two portrait print-stream
     pages become one landscape impression. Note that the placement of
     impressions onto media sheets is also controlled by the "multiple-
     document-handling" attribute as described in section 4.2.4.

  5. The "copies" and "multiple-document-handling" attributes are used
     to determine how many copies of each media instance are created and
     in what order. See sections 4.2.5 and 4.2.4 for the details.

  6. When the correct number of copies are created, the media instances
     are finished according to the values of the "finishings" attribute
     as described in 4.2.6. Note that sometimes finishing operations may
     require manual intervention to perform the finishing operations on
     the copies, especially uncollated copies. This specification allows
     any or all of the processing steps to be performed automatically or
     manually at the discretion of the Printer object.


17. APPENDIX E: Generic Directory Schema


This section defines a generic schema for an entry in a directory
service.  A directory service is a means by which service users can
locate service providers.  In IPP environments, this means that IPP
Printers can be registered (either automatically or with the help of an
administrator) as entries of type printer in the directory using an
implementation specific mechanism such as entry attributes, entry type
fields, specific branches, etc.  IPP clients can search or browse for
entries of type printer.  Clients use the directory service to find
entries based on naming, organizational contexts, or filtered searches
on attribute values of entries.  For example, a client can find all
printers in the "Local Department" context. Authentication and
authorization are also often part of a directory service so that an
administrator can place limits on end users so that they are only
allowed to find entries to which they have certain access rights.  IPP
itself does not require any specific directory service protocol or
provider.



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Note: Some directory implementations allow for the notion of "aliasing".
That is, one directory entry object can appear as multiple directory
entry object with different names for each object.  In each case, each
alias refers to the same directory entry object which refers to a single
IPP Printer object.

The generic schema is a subset of IPP Printer Job Template and Printer
Description attributes (sections 4.2 and 4.4).  These attributes are
identified as either RECOMMENDED or OPTIONAL for the directory entry
itself.  This conformance labeling is NOT the same conformance labeling
applied to the attributes of IPP Printers objects.  The conformance
labeling in this Appendix is intended to apply to directory templates
and to IPP Printer implementations that subscribe by adding one or more
entries to a directory.  RECOMMENDED attributes SHOULD be associated
with each directory entry.  OPTIONAL attributes MAY be associated with
the directory entry (if known or supported).  In addition, all directory
entry attributes SHOULD reflect the current attribute values for the
corresponding Printer object.

The names of attributes in directory schema and entries SHOULD be the
same as the IPP Printer attribute names as shown.

In order to bridge between the directory service and the IPP Printer
object, one of the RECOMMENDED directory entry attributes is the Printer
object's "printer-uri-supported" attribute.  The IPP client queries the
"printer-uri-supported" attribute in the directory entry and then
addresses the IPP Printer object using one of its URIs.  The "uri-
security-supported" attribute identifies the protocol (if any) used to
secure a channel.

The following attributes define the generic schema for directory entries
of type PRINTER:

  printer-uri-supported           RECOMMENDED    Section 4.4.1
  uri-security-supported          RECOMMENDED    Section 4.4.2
  printer-name                    RECOMMENDED    Section 4.4.3
  printer-location                RECOMMENDED    Section 4.4.4
  printer-info                    OPTIONAL       Section 4.4.5
  printer-more-info               OPTIONAL       Section 4.4.6
  printer-make-and-model          RECOMMENDED    Section 4.4.8
  charset-supported               OPTIONAL       Section 4.4.15|
  generated-natural-language-
     supported                     OPTIONAL       Section 4.4.17
  document-format-supported       RECOMMENDED    Section 4.4.19
  color-supported                 RECOMMENDED    Section 4.4.23
  finishings-supported            OPTIONAL       Section 4.2.6
  number-up-supported             OPTIONAL       Section 4.2.7
  sides-supported                 RECOMMENDED    Section 4.2.8
  media-supported                 RECOMMENDED    Section 4.2.11
  printer-resolution-supported    OPTIONAL       Section 4.2.12
  print-quality-supported         OPTIONAL       Section 4.2.13
  pages-per-minute                OPTIONAL       Section 4.4.33
  pages-per-minute-color          OPTIONAL       Section 4.4.34



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18. APPENDIX F:  Differences between the IPP/1.0 and IPP/1.1 "Model and
Semantics" Specifications


The following IPP/1.0 [IPP-MOD1.0] extensions and clarifications have
been incorporated into IPP/1.1:

  1. Section 3.1.7 - clarified that only the version number parameter
     will be carried forward into future major or minor versions of the
     protocol.
  2. Section 3.2.1.1 - clarified that the Printer object rejects a
     Print-Job request if it does not support the "compression"
     operation attribute and a client supplies it.
  3. Sections 3.2.7, 3.2.8, and 3.2.9 - added the OPTIONAL Pause-
     Printer, Resume-Printer, and Purge-Jobs operations
  4. Sections 3.3.5, 3.3.6, and 3.3.7 - added the OPTIONAL Hold-Job,
     Release-Job, and Restart-Job operations.

  5. Section 4.1.9 - added 'image-tiff' and 'application/pdf' values.

  6. Section 4.2.2 - added the 'indefinite' keyword value to the "job-
     hold-until" attribute for use with the create operations and Hold-
     Job and Restart-Job operations.

  7. Section 4.2.6 - added more enum values to the "finishings" Job
     Template attribute.

  8. Section 4.3.7.1 - added the Partitioning of Job States section.
  9. Section 4.3.8 - added the 'job-restartable' keyword value to the
     "job-state-reasons" attribute for use with the Restart-Job
     operation.
  10.    Section 4.4.2 - added the 'tls' keyword value to the "uri-
     security-supported" attribute.
  11.    Section 4.4.11 - added the 'moving-to-paused' keyword value to
     the "printer-state-reasons" attribute for use with the Pause-Job
     operation.

  12.    Section 4.4.11 - replaced the duplicate 'marker-supply-low'
     keyword with the missing 'toner-empty' keyword for the "printer-
     state-reasons" attribute.

  13.    Section 4.4.13 - added the enum values to the "operations-
     supported" attribute for the new operations.  Clarified that the
     values of this attribute are encoded as any enum, namely 32-bit
     values.
  14.    Sections 4.4.33 and 4.4.34 - added the OPTIONAL "pages-per-
     minute" and "pages-per-minute-color" Printer Description
     attributes.
  15.    Section 8.5 - added the security discussion around the new
     operator operations.
  16.    Section 17 - added the OPTIONAL "pages-per-minute" and "pages-
     per-minute-color" Printer attributes to the Directory schema.

The following changes were made to IPP/1.0 [IPP-MOD1.0] to create this
IPP/1.1 document:



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  1. Section 3.1.7, 5.2.4, and 14.1.5.4 - IPP objects MUST support both
     version 1.0 and 1.1.  Clients MUST support version 1.1 and MAY
     support version 1.0.

  2. Section 4.1.9 - deleted 'text/plain; charset=iso-10646-ucs-2',
     since binary is not legal with the 'text' type.

  3. Section 5.4, 8.2, and 8.7 - changed the IPP object security
     requirements from OPTIONAL non-standards track SSL3 to RECOMMENDED
     standards track TLS.  Changed the client security requirements from
     RECOMMENDED non-standards track SSL3 to RECOMMENDED standards track
     TLS

See also the "IPP/1.1 Encoding and Transport" [ipp-pro] document for
differences between IPP/1.0 [IPP-PRO1.0] and IPP/1.1 [IPP-PRO].










































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