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Versions: 00 01 02                                                      
ASID Working Group                                      Patrik Faltstrom
Internet-Draft                                                     Tele2
Expires: September 11, 1998                             Leslie L. Daigle
draft-ietf-asid-whoispp-02.txt           Bunyip Information Systems Inc.
Replaces: RFC-1835                                           Sima Newell
                                         Bunyip Information Systems Inc.
                                                              March 1998

                  Architecture of the Whois++ service

Status of this Memo

      This document is an Internet-Draft.  Internet-Drafts are working
      documents of the Internet Engineering Task Force (IETF), its
      areas, and its working groups.  Note that other groups may also
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      Distribution of this document is unlimited.

Abstract

   This document describes Whois++, an extension to the trivial WHOIS
   service described in RFC 954 to permit WHOIS-like servers to make
   available more structured information to the Internet.  We describe
   an extension to the simple WHOIS data model and query protocol and a
   companion extensible, distributed indexing service.  A number of
   options have also been added such as the use of multiple languages
   and character sets, more advanced search expressions, structured data
   and a number of other useful features.  An optional authentication
   mechanism for protecting all or part of the associated Whois++
   information database from unauthorized access is also described.

Table of Contents

   Part I - Whois++ Overview .................................  3
   1.1.  Purpose and Motivation ..............................  3
   1.2.  Basic Information Model .............................  4
   1.2.1.  Changes to the current WHOIS Model ................  5
   1.2.2.  Registering Whois++ servers .......................  6
   1.2.3.  The Whois++ Search Selection Mechanism ............  6
   1.2.4.  The Whois++ Architecture ..........................  7
   1.3.  Indexing in Whois++ .................................  7



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   1.4.  Getting Help ........................................  8
   1.4.1.  Minimum HELP Required .............................  8
   1.5.  Options and Constraints .............................  9
   1.6.  Formatting Responses ................................  9
   1.7.  Reporting Warnings and Errors ....................... 10
   1.8.  Privacy and Security Issues ......................... 10
   Part II - Whois++ Implementation ........................... 10
   2.1.  The Whois++ interaction model ....................... 10
   2.2.  The Whois++ Command set ............................. 11
   2.2.1.  System Commands ................................... 11
   2.2.1.1.  The COMMANDS command ............................ 12
   2.2.1.2.  The CONSTRAINTS command ......................... 13
   2.2.1.3.  The DESCRIBE command ............................ 13
   2.2.1.4.  The HELP command ................................ 13
   2.2.1.5.  The LIST command ................................ 13
   2.2.1.6.  The POLLED-BY command ........................... 13
   2.2.1.7.  The POLLED-FOR command .......................... 14
   2.2.1.8.  The SHOW command ................................ 14
   2.2.1.9.  The VERSION command ............................. 14
   2.2.2.  The Search Command ................................ 14
   2.2.2.1.  Format of a Search Term ......................... 15
   2.2.2.2.  Format of a Search String ....................... 16
   2.3.  Whois++ Constraints ................................. 16
   2.3.1.  Required Constraints .............................. 17
   2.3.2.  Optional CONSTRAINTS .............................. 17
   2.3.2.1.  The SEARCH Constraint ........................... 18
   2.3.2.2.  The FORMAT Constraint ........................... 18
   2.3.2.3.  The MAXFULL Constraint .......................... 18
   2.3.2.4.  The MAXHITS Constraint .......................... 19
   2.3.2.5.  The CASE Constraint ............................. 19
   2.3.2.6.  The AUTHENTICATE Constraint ..................... 19
   2.3.2.7.  The LANGUAGE Constraint ......................... 19
   2.3.2.8.   The INCHARSET Constraint ....................... 20
   2.3.2.9.   The INCHARSET Constraint ....................... 20
   2.3.2.10.  The IGNORE Constraint .......................... 20
   2.3.2.11.  The INCLUDE Constraint ......................... 20
   2.3.2.12.  The HOLD Constraint ............................ 20
   2.4.  Server Response Modes ............................... 21
   2.4.1.  Default Responses ................................. 21
   2.4.2.  Format of Responses ............................... 22
   2.4.3.  Syntax of a Formatted Response .................... 22
   2.4.3.1.  A FULL format response .......................... 23
   2.4.3.2.  ABRIDGED Format Response ........................ 23
   2.4.3.3.  HANDLE Format Response .......................... 23
   2.4.3.4.  SUMMARY Format Response ......................... 23
   2.4.3.5.  SERVER-TO-ASK Response .......................... 24
   2.4.4.  System Generated Messages ......................... 24
   2.5.  Compatibility with Older WHOIS Servers .............. 25
   3.  Miscellaneous ......................................... 25
   3.1.  Acknowledgements .................................... 25
   3.2.  References .......................................... 26
   3.3.  Authors' Addresses .................................. 26
   Appendix A - Some Sample Queries ........................... 27
   Appendix B - Some sample responses ........................ 28



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   Appendix C - Sample responses to system commands .......... 29
   Appendix D - Sample Whois++ session ....................... 31
   Appendix E - System messages .............................. 32
   Appendix F - The Whois++ Input Syntax ..................... 34
   Appendix G - The Whois++ Response Syntax .................. 36
   Appendix H - Description of Regular expressions ........... 39

1.  Part I - Whois++ Overview

1.1.  Purpose and Motivation

   The current NIC WHOIS service [HARR85] is used to provide a very
   limited directory service, serving information about a small number
   of Internet users registered with the DDN NIC. Over time the basic
   service has been expanded to serve additional information and similar
   services have also been set up on other hosts.  Unfortunately, these
   additions and extensions have been done in an ad hoc and
   uncoordinated manner.

   The basic WHOIS information model represents each individual record
   as a Rolodex-like collection of text. Each record has a unique
   identifier (or handle), but otherwise is assumed to have little
   structure. The current service allows users to issue searches for
   individual strings within individual records, as well as searches for
   individual record handles using a very simple query-response
   protocol.

   Despite its utility, the current NIC WHOIS service cannot function as
   a general White Pages service for the entire Internet. Given the
   inability of a single server to offer guaranteed response or
   reliability, the huge volume of traffic that a full scale directory
   service will generate and the potentially huge number of users of
   such a service, such a trivial architecture is obviously unsuitable
   for the current Internet's needs for information services.

   This document describes the architecture and protocol for Whois++, a
   simple, distributed and extensible information lookup service based
   upon a small set of extensions to the original WHOIS information
   model.  These extensions allow the new service to address the
   community's needs for a simple directory service, yet the extensible
   architecture is expected to also allow it to find applications in a
   number of other information service areas.

   Added features include an extension to the trivial WHOIS data model
   and query protocol and a companion extensible, distributed indexing
   service. A number of other options have also been added, like boolean
   operators, more powerful search constraints and search methods.  In
   addition, the data has been structured to make both the client and
   server elements of the dialogue more stringent and easily
   parsed.  An optional authentication mechanism for protecting all or
   parts of the associated Whois++ information database from
   unauthorized access is also briefly described.

   The architecture of Whois++ allows distributed maintenance of



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   the directory contents and the use of the Whois++ indexing service
   for locating additional Whois++ servers. Although a general overview
   of this service is included for completeness, the indexing extensions
   are described described separately in [WINDX].

   It should be noted that Whois++ is not backward compatible with
   WHOIS.

1.2.  The Whois++ Information Model

   The Whois++ service is based on the use of information templates,
   which consist of ordered sets of data elements (or attribute-value
   pairs).  It underlying recommendation is to use standardized
   templates where available.

   It is intended that adding structured template types to a server
   and subsequently searching through information stored in templates
   of a specified type should be simple tasks.  The creation and use of
   customized templates should also be possible with little effort,
   although their use is discouraged where appropriate standardized
   templates exist.

   Registration and schema definitions are done on an attribute by
   attribute basis, so a client that receives a record parses the
   record structure one attribute at a time. Because of this system,
   the client does not need to know the structure of the whole record,
   only individual attributes. If the client sees an unknown
   attribute, it will skip that one and continue parsing the
   subsequent attributes.  A server that defines schemas can therefore
   add its own unregistered attributes to a well-defined template type.

   We also offer methods to allow the user to constrain searches to
   desired attributes or template types, in addition to the existing
   commands for specifying handles or simple strings.

   It is expected that the minimalist approach we have taken will find
   applications where the high cost of configuring and operating
   traditional White Pages services can not currently be justified.

   Note also that the architecture makes no assumptions about the search
   and retrieval mechanisms used within individual servers.  Operators
   are free to use dedicated database formats, fast indexing software or
   even provide gateways to other directory services to store and
   retrieve information. The Whois++ server simply functions as a
   known front end, offering a simple data model and communicating
   through a well known port and query protocol. The format of both
   queries and replies has been structured to allow the use of client
   software for generating searches and displaying the results. At the
   same time, some effort has been made to keep responses legible (to
   some degree) by human users, both to ensure low entry cost and to
   ease debugging.

   The actual implemention details of an individual Whois++ search
   engine are left to the imagination of the implementor.  It is hoped



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   that the simple, extensible approach taken will encourage
   experimentation and the development of improved search engines.

1.2.1.  Changes to the current WHOIS Model

   The current WHOIS service is based upon an extremely simple data
   model.  The NIC WHOIS database consists of a series of individual
   records, each of which is identified by a single unique identifer
   (the "handle"). Each record contains one or more lines of
   information. Currently, there is no structure or implicit ordering of
   this information, although each record is implicitly concerned
   with information about a single user or service.

   We have implemented two basic changes to this model. First, we have
   structured the information within the database as collections of data
   elements that are simple attribute/value pairs. Each individual
   record contains a specified ordered set of these data elements.

   Second, we have introduced the classing of database records into
   template types. In effect, each record is based upon one template
   of a specified set; each template contains a finite and specified
   number of data elements. This classing allows users to limit
   searches to specific collections of information, such as information
   about users, services, abstracts of papers, or descriptions of
   software.

   Since the data typing is done at the attribute level, not the
   template level, it is also possible to add non-standard attributes to
   a well-known template type.

   As an addition to the model, we require that each individual Whois++
   database on the Internet be assigned a unique handle, analogous to
   the handle associated with each database record.

   The Whois++ database structure is shown in Fig. 1.

 ______________________________________________________________________
|                                                                      |
|   +  Single unique Whois++ server   handle                           |
|                                                                      |
|              _______                 _______                _______  |
|    handle3  |..  .. |      handle6  |..  .. |     handle9  |..  .. | |
|            _______  |              _______  |             _______  | |
|  handle2  |..  .. |      handle5  |..  .. |     handle8  |..  .. |   |
|           _______ |               _______ |              _______ |   |
| handle1  |..  .. |      handle4  |..  .. |     handle7  |..  .. |    |
|          |..  .. |               |..  .. |              |..  .. |    |
|           -------                 -------                -------     |
|      Template                   Template               Template      |
|       Type 1                     Type 2                 Type 3       |
|                                                                      |
|                                                                      |
|                                                                      |
|                                                                      |



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                  Architecture of the Whois++ service         March 1998


|               Fig.1 - Structure of a Whois++ database.               |
|                                                                      |
| Notes: - Entire database is identified by a single unique Whois++    |
|          serverhandle.                                               |
|        - Each record has a single unique handle.                     |
|        - Each record has a specific set of attributes, which is      |
|          determined by the Template Type used.                       |
|        - Each value associated with an attribute is a text string    |
|          of an arbitrary length.                                     |
|______________________________________________________________________|



1.2.2.  Registering Whois++ servers

   We propose that individual database handles be registered through the
   Internet Assigned Numbers Authority (the IANA), ensuring their
   uniqueness. This will allow us to specify each Whois++ entry on the
   Internet as a unique pair consisting of a server handle and a record
   handle.

   A unique registered handle is preferable to using the host's IP
   address, since it is conceivable that the Whois++ server for a
   particular domain may move over time.  If we preserve the unique
   Whois++ handle in such cases we have the option of using it for
   resource discovery and networked information retrieval (see [IIIR]
   for a discussion of resource and discovery and support issues).

   Uniqueness of server handles can be guaranteed by registering them
   with IANA.

   We believe that organizing information around a series of such
   templates will make it easier for administrators to gather and
   maintain this information and thus encourage them to make such
   information available.  At the same time, as users become more
   familiar with the data elements available within specific templates
   they will be able to specify their searches better, and the service
   will become more useful.


1.2.3.  The Whois++ Search Selection Mechanism

   The WHOIS++ search mechanism is intended to be extremely simple. A
   search command comprises one required element and one optional
   element.  The first (required) element is a set of one or more search
   terms.  The second (optional) element is a colon followed by set of
   one or more global constraints, which modify or control the search.

   Within each search term, the user may specify the template type,
   attribute, value or handle that any record returned must satisfy.
   Each search term can have an optional set of local constraints that
   apply only to that term.

   A Whois++ database may be seen as a single collection of



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   typed records. Each search term specifies a further constraint that
   the selected set of output records must satisfy. Each term may thus
   be thought of as performing a subtractive selection, in the sense
   that any record that does not fulfill the term is discarded from the
   result set.  Result sets can be further specified by supplying
   multiple search terms, related by logical connectives (AND, OR, NOT).

1.2.4.  The Whois++ Architecture

   The Whois++ directory service has an architecture which is separated
   into two components: the base level server, which is described in
   this paper, and an indexing server (described in [WINDX]). A single
   physical server can act as both a base level server and an indexing
   server.

   A base level server is one which contains only filled templates. An
   indexing server is one which contains forward knowledge (q.v.) and
   pointers to other indexing servers or base level servers.

1.3.  Indexing in Whois++

   Indexing in Whois++ is used to tie together many base level servers
   and index servers into a unified directory service.  For more
   detailed information on this subject, see [WINDX].

   Each base level server and index server that is to participate
   in the unified directory service must generate forward knowledge
   for the entries it contains. One type of forward knowledge is the
   "centroid".

   An example of a centroid is as follows.  Consider a Whois++ server
   that contains exactly three records:

        Record 1                        Record 2
        Template: Person                Template: Person
        First-Name: John                First-Name: Joe
        Last-Name: Smith                Last-Name: Smith
        Favourite-Drink: Labatt Beer    Favourite-Drink: Molson Beer

        Record 3
        Template: Domain
        Domain-Name: foo.edu
        Contact-Name: Mike Foobar

        the centroid for this server would be

        Template:       Person
        First-Name:     Joe
                        John
        Last-Name:      Smith
        Favourite-Drink:Beer
                        Labatt
                        Molson




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        Template:       Domain
        Domain-Name:    foo.edu
        Contact-Name:   Mike
                        Foobar

   An index server would then collect this centroid for this server as
   forward knowledge.

   Index servers can collect forward knowledge for any servers it
   polls.  In effect, all of the servers that the index server knows
   about can be searched with a single query to the index server; the
   index server holds the forward knowledge along with pointers to the
   servers it indexes, and can refer the query to servers which might
   hold information which satisfies the query.

   Implementors of this protocol are strongly encouraged to incorporate
   centroid generation abilities into their servers.

   Whois++ uses the Common Indexing Protocol, which was originally
   described in [WINDX] as a centroid-like object to provide index
   information (forward knowledge) about server contents.  This work
   is being extended in the IETF's FIND Working-Group.


-------------------------------------------------------------------

                              ----             ----
top level                    |    |           |    |
whois index                  |    |           |    |
servers                       ----             ----
                             /    \________     /
                            /              \   /
                        ____                ____
first level            |    |              |    |
whois index            |    |              |    |
servers                 ----                ----
                       /                   /    \
                      /                   /      \
                    ____                ____      ____
individual         |    |              |    |    |    |
whois servers      |    |              |    |    |    |
                    ----                ----      ----


                 Fig. 2 - Indexing system architecture.

-------------------------------------------------------------------

1.4.  Getting Help

   Another extension to the basic WHOIS service is the requirement that
   all servers support at least a minimal set of help commands, allowing
   users to find out information about both the individual server and
   the entire Whois++ service itself. This is done in the context of the



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   new extended information model by defining two specific template
   formats and requiring each server to offer at least one example of
   each record using these formats. The operator of each Whois++ service
   is therefor expected to have, as a minimum, a single example of
   SERVICES and HELP records, which can be accessed through appropriate
   commands.

1.4.1.  Minimum HELP Required

     Executing the command:

             DESCRIBE

     gives a brief information about the Whois++ server.

     Executing the command:

             HELP

     gives a brief description of the Whois++ service itself.

     The text of both required helped records should contain pointers to
     additional help subjects that are available.


     Executing the command:

             HELP <searchstring>

     gives information on <searchstring>.

1.5.  Options and Constraints

   The Whois++ service is based upon a minimal core set of commands and
   controlling constraints. A small set of additional optional commands
   and constraints can be supported by a server. These allow users to
   perform such tasks as provide security options, modify the
   information contents of a server or add multilingual support. The
   required set of Whois++ commands are listed in section 2.2.
   Whois++ constraints are described in section 2.3. Optional
   constraints are described in section 2.3.2.

1.6.  Formatting Responses

   The output returned by a Whois++ server is structured to allow
   machine parsing and automated handling. Of particular interest is the
   ability to return summary information about a search instead of
   having to return the entire results.

   All output of searches will be returned in one of five output
   formats, which will be one of FULL, ABRIDGED, HANDLE, SUMMARY or
   SERVER-TO-ASK.  Note that a conforming server is only required to
   support the FULL format.




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   When available, SERVER-TO-ASK format is used to indicate that a
   search cannot be completed but that one or more alternative Whois++
   servers may be able to perform the search.

   Details of each output format are specified in section 2.4.

1.7.  Reporting Warnings and Errors

   The formatted response of Whois++ commands allows the encoding of
   warning or error messages to simplify parsing and machine handling.
   The syntax of output formats are described in detail in section 2.4,
   and details of Whois++ warnings and error conditions are given in
   Appendix E.

   All system messages are numerical, but can be tagged with text. It is
   the client's decision if the text is presented to the user.

1.8.  Privacy and Security Issues

   The basic Whois++ service was conceived as a simple, unauthenticated
   information lookup service, but there are occasions when
   authentication mechanisms are required. To handle such cases, one
   optional mechanism is provided for authenticating each Whois++
   transaction.  This is the ability to name a (mutually-recognized)
   authentication scheme in the optional AUTHENTICATE  global
   constraint.

   Note that the Whois++ authentication mechanism does not dictate the
   actual authentication scheme used, it merely provides a framework for
   indicating that a particular transaction is to be authenticated, and
   the appropriate scheme to use. This mechanism is extensible and
   individual implementors are free to add additional schemes.

   Sophisticated security and authentication schemes may be proposed to
   address specific needs.  For example, the Simple Authentication and
   Security Layer (SASL) work proposed by John Myers (particularly for
   POP and IMAP) may be applicable here.


2.  Part II - Whois++ Implementation

2.1.  The Whois++ interaction model

   The Whois++ service has an assigned port number -- number 63.
   However, there is nothing inherent the Whois++ protocol or
   interaction model that prevents it from being used on any TCP
   connection on any port -- the specification of the connection is
   outside the scope of this protocol spec.  Once a connection is
   established, the server issues a banner message, and listens for
   input. The command specified in this input is processed and the
   results returned including an ending system message. If the client
   does not specify the optional HOLD constraint, the connection is
   then terminated.




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   If the server supports the optional HOLD constraint, and this
   constraint is specified as part of any command, the server continues
   to listen on the connection for another (single) line of input.
   This cycle continues as long as the sender continues to append the
   required HOLD constraint to each subsequent command.


2.2.  The Whois++ Command set

   The Whois++ command set consists of a core set of required systems
   commands, a single required search command and an set of optional
   system commands which support features that are not required by all
   servers. The set of required Whois++ system commands are listed in
   Table I. Valid search terms for the search command are described in
   Table II.

   Each Whois++ command also allows the use of one or more controlling
   constraints, which, when selected, are used to override defaults or
   otherwise modify the server's behavior. There is a core set of
   constraints that must be supported by all conforming servers:
   SEARCH (which controls the type of search performed), FORMAT (which
   determines the output format used) and MAXHITS (which determines the
   maximum number of matches that a search can return). These required
   constraints are summarized in Table III.

   An additional set of optional constraints are used to provide support
   for different character sets, provide data for the authentication
   scheme, and requesting multiple transactions during a single
   communications session. These optional constraints are listed in
   Table IV.

   It is possible, using the required COMMANDS and CONSTRAINTS system
   commands, to query any Whois++ server for its list of supported
   commands and constraints.

   Please note that the line terminator is defined as a carriage
   return and line feed (CR/LF) pair.  Also, none of the commands or
   constraints supported by Whois++ are case sensitive.  For example,
   the following are equivalent: HELP, Help, help, hElp.
   Capitalization of all letters (e.g. HELP) is used only to improve
   the legibility of this document.  Finally, "attribute value" is
   defined as "the value associated with an attribute".

2.2.1.  System Commands

   System commands are commands to the server for information or to
   control its operation. These include commands to list the template
   types available from individual servers, to obtain a single blank
   template of any available type, and commands to obtain the list of
   valid commands and constraints supported on a server.

   There are also commands to obtain the current version of the Whois++
   protocol supported, to access a simple help subsystem, to obtain a
   brief description of the service provided by the Whois++



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   server. The DESCRIBE command is intended, among other
   things, to support the automated registration of the service in
   yellow pages directory services. The required commands are listed
   in Table I.

------------------------------------------------------------------------


Short  Long Form                               Functionality
-----  ---------                               -------------
       COMMANDS        [ ':' HOLD ]          List Whois++ commands
                                             supported by this server

       CONSTRAINTS     [ ':' HOLD ]          List valid constraints
                                             supported by this server

       DESCRIBE        [ ':' HOLD ]          Describe this server,
                                             formating the response
                                             using a standard
                                             SERVICES template

 '?'   HELP [<string>  [':' (<othercnstrnts> / HOLD)
                        0*(';' (<otherconstraints> / HOLD))]]
                                             Provide help specific to
                                             this Whois++ server, using
                                             a "Help" template

       LIST            [':' (<othercnstrnts> / HOLD)
                        0*(';' (<otherconstraints> / HOLD))]
                                             List templates supported
                                             by this server

       POLLED-BY       [ ':' HOLD ]          List indexing servers
                                             that are known to poll
                                             this server

       POLLED-FOR      [ ':' HOLD ]          List information about
                                             servers this server polls

       SHOW <string>   [':' <cnstrnts>]      Show contents of template
                                             specified in <string>

       VERSION         [ ':' HOLD ]          Show the version of
                                             the protocol supported by
                                             this server

              Table I - Required Whois++ SYSTEM commands.

------------------------------------------------------------------------

   Descriptions of each command follow.  Examples of responses
   to each command are provided in Appendix C.

2.2.1.1.  The COMMANDS command



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   The COMMANDS command returns a list of commands that the server
   supports. The response is formatted as a FULL response.

2.2.1.2.  The CONSTRAINTS command

   The CONSTRAINTS command returns a list of both the constraints and
   their values that the server supports. The response is formatted as a
   FULL response, where every constraint is represented as a separate
   record. The template name for these records is CONSTRAINT.  No
   attention is paid to handles. Each record has, as a minimum, the
   following two attributes:

     - "Constraint", whose value is the constraint name
     - "Default", which shows the default value for this constraint.

   If the client is permitted to change the value of the constraint,
   there is also:

     - "Range", which contains a list of values that this
       server supports, as a comma separated list, or, if the range
       is numerical, as a pair of numbers separated with a hyphen.

   Note that, irrespective of whether a session is continued (with the
   HOLD constraint) or not, constraints are set to the default value
   unless explicitly changed with a constraint in each query.

2.2.1.3.  The DESCRIBE command

   The DESCRIBE command gives a brief description about the server in a
   "Services" template. The result is formatted as a FULL response with
   as a minimum one attribute:

     - "Text", which describes the service in a form legible by human
       users.

2.2.1.4.  The HELP command

   The HELP command takes an optional argument which is the subject on
   which to get help. The answer is formatted as a FULL format response.

2.2.1.5.  The LIST command

   The LIST command returns the name of the templates available on the
   server. The answer is formatted as a FULL format response.

2.2.1.6.  The POLLED-BY command

   The POLLED-BY command returns a list of servers and the templates and
   attribute names that those servers polled as centroids from this
   server. The format is in FULL format with two attributes, "Template"
   and "Field", whose values are lists of the names of the polled
   templates and fields, respectively.  An empty result means either
   that the server is not polled by anyone, or that it doesn't support
   indexing.



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2.2.1.7.  The POLLED-FOR command

   The POLLED-FOR command returns a list of servers that this server has
   polled, and the template and attribute names for each of those.  The
   answer is in FULL format with two attributes, Template and Field.  An
   empty result means either that the server is not polling anyone, or
   that it doesn't support indexing.

2.2.1.8.  The SHOW command

   The SHOW command takes a template name as argument and returns
   information about that template, formatted as a FULL response.
   The answer is formatted as a blank template with the requested name.

2.2.1.9.  The VERSION command

   The output format is a FULL response containg a record with template
   name VERSION. The record must have attribute name "Version", whose
   value is "2.0" for this version of the protocol.  The record may also
   have the additional fields "Program-Name" and "Program-Version" which
   gives information about the server implementation if the server so
   desires.

   If the server also supports the earlier version of the protocol,
   "1.0", two records are given back as a response to the VERSION
   command, one for each version supported.

2.2.2.  The SEARCH Command

   A SEARCH command comprises one required element and one optional
   element.  The first (required) element is a set of one or more search
   terms.  The second (optional) element is a set of global constraints,
   which modify or control the search.

   Each attribute value in the Whois++ database is divided into one or
   more words separated by whitespace:

   whitespace = 1*( %d32 / %d09 / %d10 / %d13 / %d64 )
                 ;  space  tab     LF     CR      @

   Each search term operates on every word in the attribute value.
   Two or more search terms have to be combined with boolean operators
   AND, OR or NOT. The operator AND has higher precedence than the
   operator OR, but this can be changed by the use of parentheses.

   Boolean operators function as follows for two search terms, A and
   B.  Let A1 be the result set from the first search term and B1 be the
   result set from the second search.  The operation A AND B returns the
   hits in the intersection of sets A1 and B1.  The operation A OR B
   returns the hits in the union of the sets A1 and B1.  The operation
   NOT A returns all possible results that are not in set A1.  The
   behaviour of the boolean operators can be generalized to N search
   terms where N > 2.  Note that NOT has a higher precedence than AND
   or OR, so NOT A AND B returns the hits in B that are not in A.



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   Search constraints that apply to all search terms are specified as
   global constraints. The search terms and the global constraints are
   separated with a colon (':'). Each additional global constraint is
   appended to the end of the search command, and a semicolon ';' is
   used as the delimiter between global constraints.

   If any of the search constraints can not be fulfilled, or if
   several of the specified constraints are mutually exclusive, the
   server ignores the constraints that can not be fulfilled and those
   that are mutually exclusive.  The server performs the search using
   only the remaining constraints and returns the corresponding set of
   records.

   The set of required constraints are listed in Table III. The set
   of optional constraints are listed in Table IV.

   As an option, the server may accept specifications for attributes
   to be included or excluded from a reply. Thus, users could specify
   -only- those attributes to return, or specific attributes to filter
   out, thus creating custom views.

2.2.2.1.  Format of a Search Term

   Each search term consists of one of the following:

     1) A search string

        <value>

     2) A search term specifier (as listed in Table II), followed by a
        '=', followed by a search string.  This is noted as:

        <specifier> = <value>

     3) An attribute name, followed by '=', followed by
        a search string:

        <attribute_name> = <value>


   If no search term specifier is provided, then the search will be
   applied to attribute values only. This corresponds to an identifier
   of VALUE.

   When the user specifies the search term using the form:

             "<attribute_name> = <value>"

   this is considered to be an ATTRIBUTE-VALUE search.

   For discussion of the system reply format, and selecting the
   appropriate reply format, see section 2.4.

     -------------------------------------------------------------------



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      Valid specifiers:
      -----------------

      Name                                       Functionality
      ----                                       -------------

      HANDLE                            Confine search to handles.
      VALUE                             Confine search to attribute
                                        values.


                 Table II - Valid search command term specifiers.

     -------------------------------------------------------------------

2.2.2.2.  Format of a Search String

   Special characters that need to be quoted are preceeded by a
   backslash, ''.

   Special characters are space ' ', tab, equal sign '=', comma ',',
   colon ':', backslash '', semicolon ';', asterisk '*', period '.',
   parenthesis '()', square brackets '[]', dollar sign '$' and
   circumflex '^'.

   If the search term is given in some other character set than ISO-
   8859-1, it must be specified by the constraint INCHARSET.

2.3.  Whois++ Constraints

   Constraints are intended to be hints or recommendations to the server
   about how to process a command. They may also be used to override
   default behaviour, such as requesting that a server not drop the
   connection after performing a command.

   Thus, a user might specify a search constraint as "SEARCH=exact",
   which means that the search engine is to perform an exact match
   search. The user might also specify "LANGUAGE=Fr", which means that
   the server should (if possible) display the French versions of the
   attribute values, and if possible use French in fuzzy matches. The
   server should also issue system messages in French.

   In general, constraints take the form "<constraintname>=<value>",
   where <value> is one of a specified set of valid values. The notable
   exception is "HOLD", which takes no argument.

   The CONSTRAINTS system command is used to list the search constraints
   supported by an individual server.

   If a server cannot satisfy the specified constraint, the server
   should indicate this to the user through the use of system messages.
   In such cases, the search is still performed, with the the server
   ignoring unsupported constraints.




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2.3.1.  Required Constraints

   The following CONSTRAINTS must be supported in all conforming Whois++
   servers.

     ------------------------------------------------------------------

      Format
      ------

     SEARCH=   exact / lstring

     FORMAT=   full / abridged / handle / summary

     MAXHITS=  1-<max-allowed>

     Table III - Required Whois++ constraints.

     ------------------------------------------------------------------

2.3.2.  Optional CONSTRAINTS

   The following CONSTRAINTS and constraint values are not required of a
   conforming Whois++ server, but may be supported. If supported, their
   names and supported values must be returned in the response to the
   CONSTRAINTS command.

  ---------------------------------------------------------------------

   Format
   ------

  SEARCH=       regex / fuzzy / substring

  CASE=         ignore / consider

  FORMAT=       server-to-ask

  MAXFULL=      1-<max-allowed>

  AUTHENTICATE= data

  INCHARSET=    us-ascii / iso-8859-* /
                  UNICODE-1-1-UTF-8 / UNICODE-2-0-UTF-8 / UTF-8

  OUTCHARSET=   us-ascii / iso-8859-* /
                  UNICODE-1-1-UTF-8 / UNICODE-2-0-UTF-8 / UTF-8

  LANGUAGE=     <As defined in RFC 1766 [ALVE95]>

  HOLD

  IGNORE=       <attributelist>




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  INCLUDE=      <attributelist>


  N.B.:  "UTF-8" is as defined in [RFC2279].  This is the character set
         label that should be used for UTF encoded information; the
         labels "UNICODE-2-0-UTF-8" and "UNICODE-1-1-UTF-8" are retained
         primarily for compatibility with older Whois++ servers, and
         as outlined in [RFC2279].

                Table IV - Optional Whois++ constraints.

  ----------------------------------------------------------------------

2.3.2.1.  The SEARCH Constraint

   The SEARCH constraint is used for specifying the method that is to be
   used for the search. The default method is "exact". Following is a
   definition of each search method.


   exact           The search will succeed for a word that exactly
                   matches the search string.

   substring       The search will succeed for a word that matches
                   a part of a word.

   regex           The search will succeed for a word when a regular
                   expression matches the searched data. Regular
                   expression is built up by using constructions of
                   '*', '.', '^', '$', and '[]'. For use of
                   regular expressions see Appendix H.

   fuzzy           The search will succeed for words that matches the
                   search string by using an algorithm designed to catch
                   closely related names with different spelling, e.g.
                   names with the same pronunciation.  The server
                   chooses which algorithm to use, but it may vary
                   depending on template name, attribute name and
                   language used (see Constraint Language above).

   lstring         The search will succeed for words that begins
                   with the search string.

2.3.2.2.  The FORMAT Constraint

   The FORMAT constraint describes what format the result will be in.
   Default format is FULL. For a description of each format, see Server
   Response Modes below.

2.3.2.3.  The MAXFULL Constraint

   The MAXFULL constraint sets the limit of the number of matching
   records the server allows before it enforces SUMMARY responses.  The
   client may attempt to override this value by specifying another value



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   to that constraint. Example: If, for privacy reasons, the server is
   to return the response in SUMMARY format if the number of hits
   exceeds 2, the MAXFULL constraint is set to 2 by the server.

   Regardless of what format the client asked for, the server will
   change the response format to SUMMARY when the number of matching
   records equals or exceeds this value.

2.3.2.4.  The MAXHITS Constraint

   The MAXHITS constraint sets the maximum number of records returned
   to the client in response to a query.

2.3.2.5.  The CASE Constraint

   The CASE constraint defines if the search should be case
   sensitive or not. Default value is to have case ignored.

2.3.2.6.  The AUTHENTICATE Constraint

   The AUTHENTICATE constraint describes which authentication scheme to
   use when executing the search.   Depending on the authentication
   scheme used, some other constraints may have to be specified.    The
   authentication scheme definition identifies which constraints it
   requires.


2.3.2.7.  The LANGUAGE Constraint

   The LANGUAGE constraint specifies the language in which the client
   wishes to receive responses.  It therefore specifies which attribute
   values should be presented to the user (i.e., only those in the
   specified language, or for which no language information is
   available).  It can also be used as an extra information to the
   fuzzy matching search method, and it might also be used to tell the
   server to give the system responses in another language.  This
   should preferably be handled by the client. The language codes
   defined in RFC 1766 [ALVE95] should be used as a value for the
   language constraint. In these, the case of the letters are
   insignificant.

   If a record has attribute values in different languages, and no
   LANGUAGE search constraint was given in the query, the switch
   between the different languages should be given in the response by
   the use of system messages 601 which has one argument only, the
   name of the language or one of the predefined strings "ANY" or "DEF".
   A block of alternative attribute values starts with a language
   definition like "% 601 SE". After the first language specification,
   zero or more language specifications can be given, each switching
   into the desired language. When all specific languages have been
   tagged, the specification "% 601 DEF" can be used for specifying
   default attribute values. A block of alternative attributes must
   end with "% 601 ANY".




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   The following is an example of a response using the language
   messages:

       # FULL USER LOCAL USER-DOE
       % 601 FR
        Name: Monsieur John Doe
       % 601 SV
        Name: Herr John Doe
       % 601 DEF
        Name: Mister John Doe
       % 601 ANY
        Email: jdoe@doe.pp.se
       # END

   The language specifications may be suppressed by the server (using
   the % 601 messages) if the client has explicitly, by using the global
   constraint LANGUAGE, asked for a specific language.

2.3.2.8.   The INCHARSET Constraint

   The INCHARSET constraint tells the server in which character set the
   search string itself is given. The default character set is
   ISO-8859-1.

2.3.2.9.   The OUTCHARSET Constraint

   The OUTCHARSET constraint tells the server in which character set the
   search result data (not attributenames or system information) is
   supposed to be given in. The default character set is ISO-8859-1,
   but the server may choose something else.

2.3.2.10.  The IGNORE Constraint

   The IGNORE constraint specifies which attributes NOT to include in
   the result. All other attributes will be included (as if named
   explicitly by the "include" constraint).

   If an attribute is named both with the "include" and "ignore"
   constraint, the attribute is to be included in the result, but the
   system message "% 112 Requested constraint not fulfilled" must be
   sent.

2.3.2.11.  The INCLUDE Constraint

   The INCLUDE constraint specifies which attributes to include in the
   result. All other attributes will be excluded (as if named explicitly
   by the "ignore" constraint).

   If an attribute is named both with the "include" and "ignore"
   constraint, the attribute is to be included in the result, but the
   system message must be "% 112 Requested constraint not fulfilled".

2.3.2.12.  The HOLD Constraint




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   The HOLD constraint requests that the server hold open the connection
   after sending the response to the query.  The server waits for
   another user input string.


2.4.  Server Response Modes

   The grammar for Whois++ responses is given in Appendix G, and
   described below.

   There are currently a total of five different response modes possible
   for Whois++ servers. These are FULL, ABRIDGED, HANDLE, SUMMARY and
   SERVER-TO-ASK. The syntax of each output format is specified in more
   detail in Appendix G.

     1) A FULL format response provides the complete contents of a
        template matching the specified query, including the template
        type, the server handle and an optional record handle.

     2) An ABRIDGED format response provides a brief summary, including
        (as a minimum) the server handle, the corresponding record
        handle and relevant information for that template.

     3) A HANDLE format response returns a line with information about
        the server handle and record handle for a record that matched
        the specified query.

     4) A SUMMARY response provides only a brief summary of information
        the number of matches and the list of template types in which
        the matches occurred.

     5) A SERVER-TO-ASK response only returns pointers to other index
        servers which might possibly be able to answer the specified
        query.

   The server may optionally respond with an empty result set and may
   also respond with an empty response together with a system message
   to indicate that the query was too complex for it to fulfill.

2.4.1.  Default Responses

   By default, a Whois++ server will provide FULL responses. This may be
   changed by the client with the use of the global constraint "format".

   The server will not respond with more matches than the value
   specified with the global constraint "maxhits" in any response
   format. If the number of matches exceeds this value, the server will
   issues the system message 110 (maxhits value exceeded), but will
   still show the responses, up to the number of the "maxhits"
   constraint value.  This mechanism will allow the server to hide the
   number of possible matches to a search command.


2.4.2.  Format of Responses



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   Each response consists of a numerical system generated message, which
   can be tagged with text, followed by an optional formatted response
   message, followed by a second system generated message. The formatted
   response itself can include system messages, for example for switches
   in language.

   That is:

        '%' <system messages> <CR/LF>

        [ <formatted response> ]

        '%' <system messages> <CR/LF>


   If there are no matches to a query, the system is not required to
   generate any output as a formatted response, although it must still
   generate system messages.

   For information about the standard text for system messages, see
   Appendix E.

2.4.3.  Syntax of a Formatted Response

   All formatted responses except for the HANDLE response, consist of a
   response-specific START line, followed by an optional response-
   specific data section, followed by a TERMINATION line.  The HANDLE
   response is different in that it only consists of a START line.  It
   is permissible to insert any number of lines consisting solely of
   CR/LF pairs within a formatted response to improve readability.

   Each line shall be limited to no more than 81 characters, including
   the terminating CR/LF pair.  If a line (including the required
   leading single space) would exceed 81 characters, it must be broken
   into lines of no more than 81 characters, with each continuation line
   beginning with a "+" character in the first column instead of the
   leading character.

   If an attribute value in a data section includes a line break, the
   line break must be replaced by a CR/LF pair and the following line
   begin with a "-" character in the first column, instead of the
   leading character. The attribute name is not repeated on consecutive
   lines.

   A TERMINATION line consists of a line with a '#' in the first column,
   followed by one space (ASCII 32) character, followed by the keyword
   END, followed by zero or more characters, followed by a CR/LF pair.

   A response-specific section will be one of the following:

       1) FULL Format Response
       2) ABRIDGED Format Response
       3) HANDLE Format Response
       4) SUMMARY Format Response



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       5) SERVER-TO-ASK Format Response


2.4.3.1.  A FULL format response

   A FULL format response consists of a series of responses, each
   consisting of a START line, followed by the complete template
   information for the matching record and a TERMINATION line.

   Each START line consists of a '#' in the first column, followed by
   one space character, the word "FULL", a space character,
   the name of the corresponding template type, one space
   character, the server handle, a space character, (optionally) the
   handle for the record, and a terminating CR/LF pair.

   The template information for the record will be returned as a series
   of lines consisting of a single space, followed by the corresponding
   line of the record.

   The line of the record shall consist of a single space and the
   attribute name followed by a ':', a single space, the value of that
   attribute, and a CR/LF pair.

2.4.3.2.  ABRIDGED Format Response

   Each ABRIDGED format response consists of a START line, a single line
   excerpt of the template information from each matching record and a
   TERMINATION line. The excerpt information shall include information
   that is relevant to the template type.

   The START line consists of a '#' in the first column, followed by one
   space character, the word "ABRIDGED", a space character,
   the name of the corresponding template type, a space character,
   the server handle, a space character, the handle for the
   record, and a terminating CR/LF pair.

   The abridged template information will be returned as a line,
   consisting of a single space, followed by the abridged line of the
   record and a CR/LF pair.


2.4.3.3.  HANDLE Format Response

   A HANDLE response consists of a single START line, which shall start
   with a '#' in the first column, followed by one space
   character, the word "HANDLE", a space character, the name of
   the corresponding template, a space character, the handle for
   the server, a space character, the handle for that record, and
   a terminating CR/LF pair.

2.4.3.4.  SUMMARY Format Response

   A SUMMARY format response consists of a single response,
   consisting of a line listing the number of matches to the specified



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   query, optionally a count of referrals, followed by a list of all
   template types which satisfied the query at least once.

   The START line shall begin with a '#' in the first column, be
   followed by one space character (decimal 32), the word "SUMMARY", a
   single space character, the handle for the server, and a terminating
   CR/LF pair.

   The format of the attributes in the SUMMARY format follows the
   rules for the FULL template, with the attributes "matches",
   "referrals" and "templates". "matches" and "templates" are
   mandatory, "referrals" optional.

   The first line must begin with the string "matches:", be
   followed by a space and the number of responses to the query and
   terminated by a CR/LF pair.

   The following line shall either begin with the string "templates: "
   or the string "referrals: ". The string "templates: " are followed
   by a CR/LF separated list of the name of the template types
   which matched the query.  Each line following the first which
   include the text "templates:" must begin with a '-' instead of
   a space. The string "referrals: " is followed by the number of
   referrals included in the number of hits.

2.4.3.5.  SERVER-TO-ASK Response

   A SERVER-TO-ASK response consists of information to the client about
   a server to contact next to resolve a query.  If the server has
   pointers to more than one server, it will present additional SERVER-
   TO-ASK responses.

   The SERVER-TO-ASK response will consist of a START line and a number
   of lines with attribute-value pairs, separated by CRLF. Each line is
   indented with one space. The end of a SERVER-TO-ASK response is
   indicated with a TERMINATION line.

   Each START line consists of a '#' in the first column, followed by
   one space character, the word "SERVER-TO-ASK", a space
   character, the handle of the server and a terminating CR/LF pair.

   1. "Server-Handle" - The server handle of the server pointed at.
      (req.)
   2. "Host-Name" - Hostname for the server pointed at.
   3. "Host-Port" - Portnumber for the server pointed at.
   4. "Protocol" - The protocol to use when contacting this server.
      (opt.)

   Other attributes may be present, depending on the index server.
   The default protocol to use is Whois++.

2.4.4.  System Generated Messages

   All system generated messages must have a '%' as the first



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   character, a space as the second one, followed by a three digit
   number, a space and an optional text message. The total length of the
   line must be no more than 81 characters long, including the
   terminating CR/LF pair. There is no limit to the number of system
   messages that may be generated.

   The format for multiline replies requires that every line, except the
   last, begin with "%", followed by space, the reply code, a hyphen,
   and an optional text.  The last line will begin with "%", followed by
   space, the reply code, a space and some optional text.

   System generated messages displayed before or after the formatted
   response section are expected to refer to operation of the system or
   refer to the entire query. System generated messages within the
   output of an individual record during a FULL response are expected to
   refer to that record only, and could (for example) be used to
   indicate problems with that record of the response. See Appendix E
   for a description of system messages.

2.5.  Compatibility with Older WHOIS Servers

   Note that this format, although potentially more verbose, is still in
   a human readable form. Responses from older systems that do not
   follow this format are still conformant, since their responses would
   be interpreted as being equivalent to optional text messages, without
   a formatted response.  Clients written to this specification would
   display the responses as a advisory text message, where it would
   still be readable by the user.

3.  Miscellaneous

3.1.  Acknowledgements

   This document has been through many iterations of refinement, with
   contributions of different natures along the way.  These
   acknowledgements accrue.

   The Whois++ effort began as an intensive brainstorming session at the
   24th IETF, in Boston Massachusetts.  Present at the birth, and
   contributing ideas through this early phase, were (alphabetically)
   Peter Deutsch, Alan Emtage, Jim Fullton, Joan Gargano, Brad
   Passwaters, Simon Spero, and Chris Weider. Others who have since
   helped shape this document with feedback and suggestions include
   Roxana Bradescu, Patrik Faltstrom, Kevin Gamiel, Dan Kegel, Michael
   Mealling, Mark Prior and Rickard Schoultz.

   Version 2 of the protocol spec is based on input during the lifetime
   of version 1. Special mention goes to Jeff Allen, Leslie Daigle,
   and Philippe Boucher. During the polishing of the RFC for version 2,
   important input was given by Len Charest, Clarke Anderson and others
   in the ASID working group of the IETF.

   This work was supported in part by grant 12/39/01 from the UK
   Electronic Libraries Programme (eLib), an initiative of the



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   Joint Information Systems Committee (JISC).  This grant has
   provided the opportunity to test the protocol specification
   by developing a test suite.  The challenge was not only to provide AN
   implementation that satisfied the document, but to build tools that
   would be able to respond to all POSSIBLE responses that could be
   implemented from the spec.  This lead to the contribution of some
   textual clarifications.  Specific thanks go to Bill Heelan and
   Philippe Boucher.



3.2  References

   [ALVE95]        Alvestrand H., "Tags for the Identification of
                   Languages", RFC 1766, UNINETT, March 1995.

   [RFC2234]       Crocker, D.  and P. Overell, "Augmented BNF for
                   Syntax Specifications: ABNF", RFC 2234, November
                   1997.

   [HARR85]        Harrenstein K., Stahl M., and E. Feinler,
                   "NICNAME/WHOIS", RFC 954, SRI, October 1985.

   [POST82]        Postel J., "Simple Mail Transfer Protocol", STD 10,
                   RFC 821, USC/Information Sciences Institute,
                   August 1982.

   [IIIR]          Weider C., and P. Deutsch, "A Vision of an
                   Integrated Internet Information Service", RFC 1727
                   Bunyip Information Systems, Inc., December 1994.

   [WINDX]         Weider, C., J. Fullton, and S. Spero, "Architecture
                   of the Whois++ Index Service", RFC 1913, February
                   1996.

   [RFC2279]       F. Yergeau, " UTF-8, a transformation format of ISO
                   10646", RFC 2279, January 1998.



3.3.  Authors Addresses

   Patrik Faltstrom
   Tele2
   Borgarfjordsgatan 16
   BOX 62
   194 64 Kista
   SWEDEN

   Email: paf@swip.net


   Leslie L. Daigle
   Bunyip Information Systems Inc.



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                  Architecture of the Whois++ service         March 1998


   310 Ste. Catherine St. W
   Suite 300
   Montreal, Quebec,  CANADA
   H2X 2A1

   Email:  leslie@bunyip.com


   Sima Newell
   Bunyip Information Systems Inc.
   310 Ste. Catherine St. W
   Suite 300
   Montreal, Quebec,  CANADA
   H2X 2A1

   Email:  sima@bunyip.com


Appendix A - Some Sample Queries

       author=leslie and template=user

   The result will consist of all records where attribute "author"
   matches "leslie" with case ignored. Only USER templates will be
   searched. An example of a matching attribute is
   "Author=Leslie L. Daigle".

   This is the typical case of searching.

       author=leslie and template=user:language=fr

   The result will consist of the same records as above, but if
   attributes are available in alternative languages, only the
   ones in French will be displayed. These are either the ones which
   have explicitly been tagged as having French values, or ones that
   are tagged as being in the "DEF" (default) language.

       schoultz and rick;search=lstring

   The result will consist of all records which have one attribute value
   matching "schoultz" exactly (because the default search type is
   exact) and one attribute with "rick" as leading substring, both with
   case ignored. One example is "Name=Rickard Schoultz".

       value=phone;search=substring

   The result will consist of all records which have attribute values
   matching *phone*, for example the record "Name=Acme telephone inc.",
   but will not match the attribute name "phone". (Since term specifier
   is "value" by default, the search term could just as well have been
   simply "phone").

      ucdavis;search=substring and (gargano or joan):include=name,email




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   This search command will find records which have records containing
   the words "gargano" or "joan" somewhere in the record, and has the
   word "ucdavis" somewhere in a word. The result will only show the
   "name" and "email" fields.

Appendix B - Some sample responses

      1) FULL format responses:

      # FULL USER SERVERHANDLE1 PD45
       Name: Peter Deutsch
       email: peterd@bunyip.com
      # END
      # FULL USER SERVERHANDLE1 AE1
       Name: Alan Emtage
       email: bajan@bunyip.com
      # END
      # FULL USER SERVERHANDLE1 NW1
       Name: Nick West
       Favourite-Bicycle-Forward-Wheel-Brand: New Bicy
      +cles Acme Inc.
       email: nick@bicycle.acme.com
       My-favourite-song: Happy birthday to you!
      -Happy birthday to you!
      -Happy birthday dear Nick!
      -Happy birthday to you.
      # END
      # FULL SERVICES SERVERHANDLE1 WWW1
       Type: World Wide Web
       Location: the world
      # END

                          --------------------


      2) An ABRIDGED format response:

      # ABRIDGED USER SERVERHANDLE1 PD45
       Peter Deutsch             peterd@bunyip.com
      # END
      # ABRIDGED USER SERVERHANDLE1 AE1
       Alan Emtage               bajan@bunyip.com
      # END
      # ABRIDGED USER SERVERHANDLE1 WWW1
       World Wide Web            the world
      # END


                          --------------------


      3) HANDLE format responses:





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      # HANDLE USER SERVERHANDLE1 PD45
      # HANDLE USER SERVERHANDLE1 AE1
      # HANDLE SERVICES SERVERHANDLE1 WWW1


                          --------------------

      4) A SUMMARY format response:

      # SUMMARY SERVERHANDLE1
       Matches: 35
       Referrals: 2
       Templates: User
      -Services
      -Abstracts
      # END

Appendix C - Sample responses to system commands

   C.1 Response to the LIST command

      # FULL LIST SERVERHANDLE1
       Templates: USER
      -SERVICES
      -HELP
      # END


   C.2 Response to the SHOW command

      This example shows the result after issuing "show user":

      # FULL USER SERVERHANDLE1
        Name:
        Email:
        Work-Phone:
        Organization-Name:
        City:
        Country:
      # END

   C.3 Response to the POLLED-BY command

      # FULL POLLED-BY SERVERHANDLE1
       Server-handle: serverhandle2
       Cached-Host-Name: sunic.sunet.se
       Cached-Host-Port: 7070
       Template: USER
       Field: ALL
      # END
      # FULL POLLED-BY SERVERHANDLE1
       Server-handle: serverhandle3
       Cached-Host-Name: kth.se
       Cached-Host-Port: 7070



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       Template: ALL
       Field: Name,Email
      # END


   C.4 Response to the POLLED-FOR command

      # FULL POLLED-FOR SERVERHANDLE1
       Server-Handle: serverhandle5
       Template: ALL
       Field: Name,Address,Job-Title,Organization-Name,
      +Organization-Address,Organization-Name
      # END
      # FULL POLLED-FOR SERVERHANDLE1
       Server-Handle: serverhandle4
       Template: USER
       Field: ALL
      # END


   C.5 Response to the VERSION command

      # FULL VERSION BUNYIP.COM
       Version: 2.0
       Program-Name: Digger
       Program-Version: 3.0b1
       Program-Author: Bunyip Information Systems Inc.
       Program-Author-Email: digger-info@bunyip.com
       Bug-Report-Email: digger-bugs@bunyip.com
      # END


   C.6 Response to the CONSTRAINTS command

      # FULL CONSTRAINTS SERVERHANDLE1
       CONSTRAINT: maxhits
       DEFAULT: 100
       RANGE: 0-100
      # END
      # FULL CONSTRAINTS SERVERHANDLE1
       CONSTRAINT: case
       DEFAULT: ignore
       RANGE: ignore, consider
      # END
      # FULL CONSTRAINTS SERVERHANDLE1
       CONSTRAINT: search
       DEFAULT: exact
       RANGE: exact, lstring, substring, fuzzy
      # END
      # FULL CONSTRAINTS SERVERHANDLE1
       CONSTRAINT: language
       DEFAULT: DEF
       RANGE: FR, EN, SV, ANY, DEF
      # END



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      # FULL CONSTRAINTS SERVERHANDLE1
       CONSTRAINT: incharset
       DEFAULT: ISO-8859-1
       RANGE: ISO-8859-1, UTF-8
      # END
      # FULL CONSTRAINTS SERVERHANDLE1
       CONSTRAINT: outcharset
       DEFAULT: ISO-8859-1
       RANGE: ISO-8859-1, UTF-8, HTML
      # END

   C.7 Response to the COMMANDS command

      # FULL COMMANDS SERVERHANDLE1
       Commands: commands
      -constraints
      -describe
      -help
      -list
      -polled-by
      -polled-for
      -show
      -version
      # END





Appendix D - Sample Whois++ session

   Below is an example of a session between a client and a server. The
   angle brackets to the left is not part of the communication, but is
   just put there to denote the direction of the communication between
   the server or the client. Text appended to '>' means messages from
   the server and '<' from the client.

     Client connects to the server

     >% 220-Welcome to
     >% 220-the Whois++ server
     >% 220 at ACME inc.
     <name=Nick:hold
     >% 200 Command okay
     >
     ># FULL USER ACME.COM NW1
     > name: Nick West
     > email: nick@acme.com
     ># END
     ># SERVER-TO-ASK ACME.COM
     > Server-Handle: SUNETSE01
     > Host-Name: whois.sunet.se
     > Host-Port: 7070
     ># END



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     ># SERVER-TO-ASK ACME.COM
     > Server-Handle: KTHSE01
     ># END
     >% 226 Transfer complete
     <version
     >% 200 Command okay
     ># FULL VERSION ACME.COM
     > Version: 2.0
     ># END
     >% 226 Transfer complete
     >% 203 Bye
     Server closes the connection

   In the example above, the client connected to a Whois++ server and
   queried for all records where the attribute "name" equals "Nick", and
   asked the server not to close the connection after the response by
   using the global constraint "HOLD".

   The server responds with one record and a pointer to two other
   servers that either holds records or pointers to other servers.

   The client continues with asking for the servers version number
   without using the HOLD constraint.  After responding with protocol
   version, the server closes the connection.

   Note that each response from the server begins system message 200
   (Command OK), and ends with system message 226 (Transfer Complete).

Appendix E - System messages

   A system message begins with a '%', followed by a space and a three
   digit number, a space, and an optional text message. The line message
   must be no more than 81 characters long, including the terminating CR
   LF pair. There is no limit to the number of system messages that may
   be generated.

   A multiline system message have a hyphen instead of a space in column
   6, immediately after the numeric response code in all lines, except
   the last one, where the space is used.

     Example 1

     % 200 Command okay

     Example 2

     % 220-Welcome to
     % 220-the Whois++ server
     % 220 at ACME inc.

   The client is not expected to parse the text part of the response
   message except when receiving reply 600 or 601, in which case the
   text part is in the former case the name of a character set that
   will be used by the server in the rest of the response, and in the



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   latter case when it specifies what language the attribute value is
   in.  The valid values for characters sets is specified in the
   "characterset" list in the grammar in Appendix F.

   The theory of reply codes is described in Appendix E in STD 10, RFC
   821 [POST82].

------------------------------------------------------------------------

List of system response codes
------------------------------

110 Too many hits                         The number of matches exceeded
                                          the value specified by the
                                          maxhits constraint. Server
                                          will still reply with as many
                                          records as "maxhits" allows.

111 Requested constraint not supported    One or more constraints in
                                          query is not implemented, but
                                          the search is still done.

112 Requested constraint not fulfilled   One or more constraints in
                                          query has unacceptable value
                                          and was therefore not used,
                                          but the search is still done.

200 Command Ok                            Command accepted (i.e., syntax
                                          okay, will be executed).
                                          The client must wait for a
                                          transaction end system
                                          message.

201 Command Completed successfully        Command accepted and executed.

203 Bye                                   Server is closing connection

220 Service Ready                         Greeting message. Server is
                                          accepting commands.

226 Transaction complete                  End of data. All responses to
                                          query are sent.

430 Authentication needed                 Client requested information
                                          that needs authentication.

500 Syntax error

502 Search expression too complicated     This message is sent when the
                                          server is not able to resolve
                                          a query (i.e. when a client
                                          sent a regular expression that
                                          is too deeply nested).




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530 Authentication failed                 The authentication phase
                                          failed.

600 <token>                               Subsequent attribute values
                                          are encoded in the character
                                          set specified by <token>.

601 <token>                               Subsequent attribute values
                                          are in the language specified
                                          by <token>.

601 DEF                                   Subsequent attribute values
                                          are default values, i.e. they
                                          should be used for all languages
                                          not specified by "601 <token>"
                                          since last "601 ANY" message.

601 ANY                                   Subsequent attribute values
                                          are for all languages.

                    Table V - System response codes

------------------------------------------------------------------------

Appendix F - The Whois++ Input Grammar

The following grammar, which uses BNF-like notation as defined in
[RFC2234] defines the set of acceptable input to a Whois++ server.

N.B.:  As outlined in the ABNF definition, rule names and string
literals are in the US-ASCII character set, and are case-insensitive.


   whois-command   =   ( system-command [":" "hold"]
                       / terms [":" globalcnstrnts] ) nl

   system-command  =   "constraints"
                       / "describe"
                       / "commands"
                       / "polled-by"
                       / "polled-for"
                       / "version"
                       / "list"
                       / "show" [1*sp bytestring]
                       / "help" [1*sp bytestring]
                       / "?" [bytestring]

   terms           =   and-expr *("or" and-expr)

   and-expr        =   not-expr *("and" not-expr)

   not-expr        =   ["not"] (term / ( "(" terms ")" ))

   term            =   generalterm / specificterm



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                       / combinedterm

   generalterm     =   bytestring

   specificterm    =   specificname "=" bytestring

   specificname    =   "handle" / "value"

   combinedterm    =   attributename "=" bytestring

   globalcnstrnts  =   globalcnstrnt *(";" globalcnstrnt)

   globalcnstrnt   =   "format" "=" format
                       / "maxfull" "=" 1*digit
                       / "maxhits" "=" 1*digit
                       / opt-globalcnst

   opt-globalcnst  =   "hold"
                       / "authenticate" "=" auth-method
                       / "language" "=" language
                       / "incharset" "=" characterset
                       / "ignore" "=" bytestring
                       / "include" "=" bytestring

   format          =   "full" / "abridged" / "handle" / "summary"
                       / "server-to-ask"

   auth-method     =  bytestring

   language        = <The language code defined in RFC1766 [ALVE95]>

   characterset    =   "us-ascii" / "iso-8859-1" / "iso-8859-2" /
                       "iso-8859-3" / "iso-8859-4" / "iso-8859-5" /
                       "iso-8859-6" / "iso-8859-7" / "iso-8859-8" /
                       "iso-8859-9" / "iso-8859-10" /
                       "UNICODE-1-1-UTF-8" / "UNICODE-2-0-UTF-8"
                       "UTF-8"

                         ;"UTF-8" is as defined in [RFC2279].  This is
                         ;the character set label that should be used
                         ;for UTF encoded information; the labels
                         ;"UNICODE-2-0-UTF-8" and "UNICODE-1-1-UTF-8"
                         ;are retained primarily for compatibility with
                         ;older Whois++ servers (and as outlined in
                         ;[RFC2279]).


   searchvalue     =   "exact" / "substring" / "regex" / "fuzzy"
                       / "lstring"

   casevalue       =   "ignore" / "consider"

   bytestring          =   0*charbyte




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   attributename   =   1*attrbyte

   charbyte        =   "

   normalbyte      =   <%d33-255, except specialbyte>

   attrbyte        =   <%d33-127 except specialbyte> /
                       "

   specialbyte     =   " " / tab / "=" / "," / ":" / ";" / "
                       "*" / "." / "(" / ")" / "[" / "]" / "^" /
                       "$" / "!" / "?"

   tab             =  %d09
   sp              =  %d32        ; space

   digit           =   "0" / "1" / "2" / "3" / "4" /
                       "5" / "6" / "7" / "8" / "9"

   nl              =   %d13 %d10   ; CR LF


   NOTE: Blanks that are significant to a query must be escaped.  The
   following characters, when significant to the query, may be preceded
   and/or followed by a single blank:

     : ; , ( ) = !



Appendix G - The Whois++ Response Grammar

The following grammar, which uses ABNF-like notation as defined in
[RFC2234], defines the set of responses expected from a Whois++ server
upon receipt of a valid Whois++ query.

N.B.:  As outlined in the ABNF definition, rule names and string
literals are in the US-ASCII character set, and are case-insensitive.


   server          =   goodmessage mnl output mnl endmessage nl
                     / badmessage nl endmessage nl

   output          =   full / abridged / summary / handle

   full            =   0*(full-record / server-to-ask)

   abridged        =   0*(abridged-record / server-to-ask)

   summary         =   summary-record

   handle          =   0*(handle-record / server-to-ask)

   full-record     =   "# FULL " template serverhandle localhandle



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                              system-nl
                       1*(fulldata system-nl)
                       "# END" system-nl

   abridged-record =   "# ABRIDGED " template serverhandle localhandle
                           system-nl
                       abridgeddata
                       "# END" system-nl

   summary-record   =  "# SUMMARY " serverhandle system-nl
                       summarydata
                       "# END" system-nl

   handle-record    =  "# HANDLE " template serverhandle localhandle
                           system-nl

   server-to-ask   =   "# SERVER-TO-ASK " serverhandle system-nl
                       server-to-askdata
                       "# END" system-nl

   fulldata        =   " " attributename ": " attributevalue

   abridgeddata    =   " " 0*( attributevalue / tab )

   summarydata     =   " Matches: " number system-nl
                       [" Referrals: " number system-nl]
                       " Templates: " template 0*( system-nl "-"
                                                   template)

   server-to-ask-data = " Server-Handle:" serverhandle system-nl
                        " Host-Name: " hostname system-nl
                        " Host-Port: " number system-nl
                        [" Protocol: " prot system-nl]
                        0*(" " labelstring ": " labelstring system-nl)


   attributename   =   1*attrbyte

   attrbyte        =   <%d33-127 except specialbyte>

   attributevalue  =   longstring

   template        =   labelstring

   serverhandle    =   labelstring

   localhandle     =   labelstring

   hostname        =   labelstring

   prot            =   labelstring

   longstring      =   bytestring 0*( nl ( "+" / "-" ) bytestring )




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   bytestring      =   0*charbyte

   labelstring     =   0*restrictedbyte

   restrictedbyte  =   <%d32-%d255 except specialbyte>

   charbyte        =   <%d32-%d255 except nl>

   specialbyte     =   ":" / " " / tab / nl

   tab             =   %d09

   mnl             =   1*system-nl

   system-nl       =   nl [ 1*(message nl) ]

   nl              =   %d13 %d10

   message         =   [1*( messagestart "-" bytestring nl)]
                       messagestart " " bytestring nl

   messagestart    =   "% " digit digit digit

   goodmessage     =   [1*( goodmessagestart "-" bytestring nl)]
                       goodmessagestart " " bytestring nl

   goodmessagestart=   "% 200"

   messagestart    =   "% " digit digit digit

   badmessage      =   [1*( badmessagestart "-" bytestring nl)]
                       badmessagestart " " bytestring nl

   badmessagestart =   "% 5" digit digit

   endmessage      =   endmessageclose / endmessagecont

   endmessageclose =   [endmessagestart " " bytestring nl]
                       byemessage

   endmessagecont  =   endmessagestart " " bytestring nl

   endmessagestart =   "% 226"

   byemessage      =   byemessagestart " " bytestring nl

   endmessagestart =   "% 203"

   number          =   1*( digit )

   digit           =   "0" / "1" / "2" / "3" / "4" / "5" /
                       "6" / "7" / "8" / "9"





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Appendix H - Description of Regular expressions

   The regular expressions described in this section are the same as
   used in many other applications and operating systems. However, it
   is very simple and does not include logical operators AND and OR.

   Searches using regular expressions always use substring
   matching except when the regular expression contains the characters
   '^' or '$'.

       Character                                Function
       ---------                                --------

        <any except those listed in this table> Matches itself

        .                                       Matches any character

        a*                                      Matches zero or more 'a'

        [ab]                                    Matches 'a' or 'b'

        [a-c]                                   Matches 'a', 'b' or 'c'

        ^                                       Matches beginning of
                                                a token

        $                                       Matches end of a token

          Examples
          ---------

            String         Matches       Doesn't match
            -------        -------       -------------
             hello          xhelloy         heello
             h.llo          hello           helio
             h.*o           hello           helloa
             h[a-f]llo      hello           hgllo
             ^he.*          hello           ehello
             .*lo$          hello           helloo


















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