Network Working Group                                   J. Gregorio, Ed.
Internet-Draft                                           BitWorking, Inc
Expires: December 25, 2006                               B. de hOra, Ed.
                                                           Propylon Ltd.
                                                           June 23, 2006


                      The Atom Publishing Protocol
                   draft-ietf-atompub-protocol-09.txt

Status of this Memo

   By submitting this Internet-Draft, each author represents that any
   applicable patent or other IPR claims of which he or she is aware
   have been or will be disclosed, and any of which he or she becomes
   aware will be disclosed, in accordance with Section 6 of BCP 79.

   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 at
   http://www.ietf.org/shadow.html.

   This Internet-Draft will expire on December 25, 2006.

Copyright Notice

   Copyright (C) The Internet Society (2006).

Abstract

   The Atom Publishing Protocol (APP) is an application-level protocol
   for publishing and editing Web resources.  The protocol is based on
   HTTP transport of Atom-formatted representations.  The Atom format is
   documented in the Atom Syndication Format (RFC4287).

Editorial Note




Gregorio & de hOra      Expires December 25, 2006               [Page 1]


Internet-Draft        The Atom Publishing Protocol             June 2006


   To provide feedback on this Internet-Draft, join the atom-protocol
   mailing list (http://www.imc.org/atom-protocol/index.html) [1].

Table of Contents

   1.   Introduction . . . . . . . . . . . . . . . . . . . . . . . .   4
   2.   Notational Conventions . . . . . . . . . . . . . . . . . . .   5
   3.   Terminology  . . . . . . . . . . . . . . . . . . . . . . . .   6
   4.   Protocol Model . . . . . . . . . . . . . . . . . . . . . . .   7
   5.   Protocol Operations  . . . . . . . . . . . . . . . . . . . .   8
     5.1  Retrieving an Introspection Document . . . . . . . . . . .   8
     5.2  Creating a Resource  . . . . . . . . . . . . . . . . . . .   8
     5.3  Editing a Resource . . . . . . . . . . . . . . . . . . . .   8
       5.3.1  Retrieving a Resource  . . . . . . . . . . . . . . . .   9
       5.3.2  Updating a Resource  . . . . . . . . . . . . . . . . .   9
       5.3.3  Deleting a Resource  . . . . . . . . . . . . . . . . .   9
     5.4  Listing Collection Members . . . . . . . . . . . . . . . .  10
     5.5  Use of HTTP Response codes . . . . . . . . . . . . . . . .  10
   6.   XML-related Conventions  . . . . . . . . . . . . . . . . . .  11
     6.1  Referring to Information Items . . . . . . . . . . . . . .  11
     6.2  XML Namespace Usage  . . . . . . . . . . . . . . . . . . .  11
     6.3  Use of xml:base and xml:lang . . . . . . . . . . . . . . .  11
     6.4  RELAX NG Schema  . . . . . . . . . . . . . . . . . . . . .  12
   7.   Introspection Documents  . . . . . . . . . . . . . . . . . .  13
     7.1  Example  . . . . . . . . . . . . . . . . . . . . . . . . .  13
     7.2  Element Definitions  . . . . . . . . . . . . . . . . . . .  14
       7.2.1  The "app:service" Element  . . . . . . . . . . . . . .  14
       7.2.2  The "app:workspace" Element  . . . . . . . . . . . . .  14
       7.2.3  The "app:collection" Element . . . . . . . . . . . . .  15
       7.2.4  The "app:accept" Element . . . . . . . . . . . . . . .  16
   8.   Collections  . . . . . . . . . . . . . . . . . . . . . . . .  17
     8.1  Creating resources with POST . . . . . . . . . . . . . . .  17
     8.2  Example  . . . . . . . . . . . . . . . . . . . . . . . . .  17
     8.3  The 'edit' Link  . . . . . . . . . . . . . . . . . . . . .  19
     8.4  Media Resources and Media Link Entries . . . . . . . . . .  19
       8.4.1  Title: Header  . . . . . . . . . . . . . . . . . . . .  20
       8.4.2  Example  . . . . . . . . . . . . . . . . . . . . . . .  20
     8.5  Editing Entries with Foreign Markup  . . . . . . . . . . .  21
   9.   Listing Collections  . . . . . . . . . . . . . . . . . . . .  22
     9.1  Collection Paging  . . . . . . . . . . . . . . . . . . . .  22
   10.  Atom Format Link Relation Extensions . . . . . . . . . . . .  24
     10.1   The "edit" Link Relation . . . . . . . . . . . . . . . .  24
     10.2   The "edit-media" Link Relation . . . . . . . . . . . . .  24
   11.  Atom Publishing Control Extensions . . . . . . . . . . . . .  25
     11.1   The Atom Publishing Control Namespace  . . . . . . . . .  25
     11.2   The "pub:control" Element  . . . . . . . . . . . . . . .  25
       11.2.1   The "pub:draft" Element  . . . . . . . . . . . . . .  25
   12.  Securing the Atom Protocol . . . . . . . . . . . . . . . . .  26



Gregorio & de hOra      Expires December 25, 2006               [Page 2]


Internet-Draft        The Atom Publishing Protocol             June 2006


   13.  Security Considerations  . . . . . . . . . . . . . . . . . .  27
   14.  IANA Considerations  . . . . . . . . . . . . . . . . . . . .  28
   15.  References . . . . . . . . . . . . . . . . . . . . . . . . .  30
     15.1   Normative References . . . . . . . . . . . . . . . . . .  30
     15.2   Informative References . . . . . . . . . . . . . . . . .  31
        Authors' Addresses . . . . . . . . . . . . . . . . . . . . .  32
   A.   Contributors . . . . . . . . . . . . . . . . . . . . . . . .  33
   B.   RELAX NG Compact Schema  . . . . . . . . . . . . . . . . . .  34
   C.   Revision History . . . . . . . . . . . . . . . . . . . . . .  37
        Intellectual Property and Copyright Statements . . . . . . .  40









































Gregorio & de hOra      Expires December 25, 2006               [Page 3]


Internet-Draft        The Atom Publishing Protocol             June 2006


1.  Introduction

   The Atom Publishing Protocol is an application-level protocol for
   publishing and editing Web resources using HTTP [RFC2616] and XML 1.0
   [W3C.REC-xml-20040204].  The protocol supports the creation of
   arbitrary web resources and provides facilities for:

   o  Collections: Sets of resources, which can be retrieved in whole or
      in part.

   o  Introspection: Discovering and describing collections.

   o  Editing: Creating, updating and deleting resources.






































Gregorio & de hOra      Expires December 25, 2006               [Page 4]


Internet-Draft        The Atom Publishing Protocol             June 2006


2.  Notational Conventions

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in [RFC2119].

   Note: The Introspection Document allows the use of IRIs [RFC3987], as
   well as URIs [RFC3986].  Every URI is an IRI, so any URI can be used
   where an IRI is needed.  How to map an IRI to a URI is specified in
   Section 3.1 of Internationalized Resource Identifiers (IRIs)
   [RFC3987].








































Gregorio & de hOra      Expires December 25, 2006               [Page 5]


Internet-Draft        The Atom Publishing Protocol             June 2006


3.  Terminology

   For convenience, this protocol can be referred to as the "Atom
   Protocol" or "APP".

   URI/IRI - A Uniform Resource Identifier and Internationalized
   Resource Identifier.  These terms and the distinction between them
   are defined in [RFC3986] and [RFC3987].  Note that IRIs are mapped to
   URIs before dereferencing takes place.

   Resource - A network-accessible data object or service identified by
   an IRI, as defined in [RFC2616].  See [W3C.REC-webarch-20041215] for
   further discussion on resources.

   The phrase "the URI of a document" in this specification is shorthand
   for "an URI which, when dereferenced, is expected to produce that
   document as a representation".

   Representation - An entity included with a request or response as
   defined in [RFC2616].

   Collection - A resource that contains a set of member IRIs.  See
   Section 8.

   Member - A resource whose IRI is listed in a Collection.

   Introspection Document - A document that describes the location and
   capabilities of one or more Collections.  See Section 7.























Gregorio & de hOra      Expires December 25, 2006               [Page 6]


Internet-Draft        The Atom Publishing Protocol             June 2006


4.  Protocol Model

   The Atom Publishing Protocol uses HTTP to edit and author web
   resources.  The Atom Protocol uses the following HTTP methods:

   o  GET is used to retrieve a representation of a resource or perform
      a query.

   o  POST is used to create a new, dynamically-named resource.

   o  PUT is used to update a known resource.

   o  DELETE is used to remove a resource.

   Along with operations on resources the Atom Protocol provides
   structures, called Collections, for managing and organising
   resources, called Members.  Collections contain the IRIs of, and
   metadata about, their Member resources.  Atom Protocol clients can
   use Introspection documents, which represent server-defined groups of
   Collections, to initialize the process of creating and editing
   resources.

   Note that when an IRI is used for resource retrieval over HTTP, the
   IRI is first converted to a URI according the procedure defined in
   [RFC3987] section 3.1.  The resource that the IRI locates is the same
   as the one located by the URI obtained after converting the IRI.

























Gregorio & de hOra      Expires December 25, 2006               [Page 7]


Internet-Draft        The Atom Publishing Protocol             June 2006


5.  Protocol Operations

5.1  Retrieving an Introspection Document

   Client                                     Server
     |                                           |
     |  1.) GET to URI of Introspection Document |
     |------------------------------------------>|
     |                                           |
     |  2.) Introspection Document               |
     |<------------------------------------------|
     |                                           |

   1.  The client sends a GET request to the URI of the Introspection
       Document.

   2.  The server responds with the document enumerating the IRIs of a
       set of Collections and the capabilities of those Collections
       supported by the server.  The content of this document can vary
       based on aspects of the client request, including, but not
       limited to, authentication credentials.


5.2  Creating a Resource

   Client                                     Server
     |                                           |
     |  1.) POST to URI of Collection            |
     |------------------------------------------>|
     |                                           |
     |  2.) 201 Created                          |
     |<------------------------------------------|
     |                                           |

   1.  The client POSTs a representation of the Member to the URI of the
       collection.

   2.  If the Member resource was created successfully, the server
       responds with a status code of 201 and a Location: header that
       contains the URI of the newly created resource.


5.3  Editing a Resource

   Once a resource has been created and its URI is known, that URI can
   be used to retrieve, update, and delete the resource.





Gregorio & de hOra      Expires December 25, 2006               [Page 8]


Internet-Draft        The Atom Publishing Protocol             June 2006


5.3.1  Retrieving a Resource

   Client                                     Server
     |                                           |
     |  1.) GET to Member URI                    |
     |------------------------------------------>|
     |                                           |
     |  2.) Member Representation                |
     |<------------------------------------------|
     |                                           |

   1.  The client sends a GET request to the Member's URI to retrieve
       its representation.

   2.  The server responds with the representation of the resource.


5.3.2  Updating a Resource

   Client                                     Server
     |                                           |
     |  1.) PUT to Member URI                    |
     |------------------------------------------>|
     |                                           |
     |  2.) 200 OK                               |
     |<------------------------------------------|

   1.  The client PUTs an updated representation to the Member's URI.

   2.  Upon a successful update of the resource the server responds with
       a status code of 200.


5.3.3  Deleting a Resource

   Client                                     Server
     |                                           |
     |  1.) DELETE to Member URI                 |
     |------------------------------------------>|
     |                                           |
     |  2.) 200 Ok                               |
     |<------------------------------------------|
     |                                           |

   1.  The client sends a DELETE request to the Member's URI.

   2.  Upon the successful deletion of the resource the server responds
       with a status code of 200.



Gregorio & de hOra      Expires December 25, 2006               [Page 9]


Internet-Draft        The Atom Publishing Protocol             June 2006


5.4  Listing Collection Members

   To list the members of a Collection the client sends a GET request to
   the Collection's URI.  An Atom Feed Document is returned containing
   one Atom Entry for each member resource.  See Section 9 and
   Section 10 for a description of the feed contents.

   Client                          Server
     |                                |
     |  1.) GET to Collection URI     |
     |------------------------------->|
     |                                |
     |  2.) 200 OK, Atom Feed Doc     |
     |<-------------------------------|
     |                                |

   1.  The client sends a GET request to the Collection's URI.

   2.  The server responds with an Atom Feed Document containing the
       IRIs of the collection members.


5.5  Use of HTTP Response codes

   The Atom Protocol uses the response status codes defined in HTTP to
   indicate the success or failure of an operation.  Consult the HTTP
   specification [RFC2616] for detailed definitions of each status code.
   It is RECOMMENDED that entities contained within HTTP 4xx and 5xx
   responses include a human-readable explanation of the error.






















Gregorio & de hOra      Expires December 25, 2006              [Page 10]


Internet-Draft        The Atom Publishing Protocol             June 2006


6.  XML-related Conventions

   The Atom Protocol Introspection format is specified in terms of the
   XML Information Set [W3C.REC-xml-infoset-20040204], serialised as XML
   1.0 [W3C.REC-xml-20040204].  Atom Publishing Protocol Documents MUST
   be well-formed XML.  This specification does not define any DTDs for
   Atom Protocol, and hence does not require them to be "valid" in the
   sense used by XML.

6.1  Referring to Information Items

   This specification uses a shorthand for two common terms: the phrase
   "Information Item" is omitted when discussing Element Information
   Items and Attribute Information Items.  Therefore, when this
   specification uses the term "element," it is referring to an Element
   Information Item in Infoset terms.  Likewise, when it uses the term
   "attribute," it is referring to an Attribute Information Item.

6.2  XML Namespace Usage

   The namespace name [W3C.REC-xml-names-19990114] for the XML format
   described in this specification is:

   http://purl.org/atom/app#

   This specification uses the prefix "app:" for the namespace name.
   The choice of namespace prefix is not semantically significant.

   The "app:" namespace is reserved for future forward-compatible
   revisions of the Atom Publishing Protocol.  Future versions of this
   specification could add new elements and attributes to the markup
   vocabulary.  Software written to conform to this version of the
   specification will not be able to process such markup correctly and,
   in fact, will not be able to distinguish it from markup error.  For
   the purposes of this discussion, unrecognized markup from the Atom
   Publishing Protocol vocabulary will be considered "foreign markup".

   This specification also uses the prefix "atom:" for
   "http://www.w3.org/2005/Atom", the namespace name of the Atom
   Syndication Format [RFC4287].

6.3  Use of xml:base and xml:lang

   XML elements defined by this specification MAY have an xml:base
   attribute [W3C.REC-xmlbase-20010627].  When xml:base is used, it
   serves the function described in section 5.1.1 of URI Generic Syntax
   [RFC3986], establishing the base URI (or IRI) for resolving any
   relative references found within the effective scope of the xml:base



Gregorio & de hOra      Expires December 25, 2006              [Page 11]


Internet-Draft        The Atom Publishing Protocol             June 2006


   attribute.

   Any element defined by this specification MAY have an xml:lang
   attribute, whose content indicates the natural language for the
   element and its descendents.  The language context is only
   significant for elements and attributes declared to be "Language-
   Sensitive" by this specification.  Requirements regarding the content
   and interpretation of xml:lang are specified in Section 2.12 of XML
   1.0 [W3C.REC-xml-20040204].
   appCommonAttributes =
      attribute xml:base { atomUri }?,
      attribute xml:lang { atomLanguageTag }?,
      undefinedAttribute*


6.4  RELAX NG Schema

   Some sections of this specification are illustrated with fragments of
   a non-normative RELAX NG Compact schema [RNC].  A complete schema
   appears in Appendix B.  However, the text of this specification
   provides the definition of conformance.






























Gregorio & de hOra      Expires December 25, 2006              [Page 12]


Internet-Draft        The Atom Publishing Protocol             June 2006


7.  Introspection Documents

   For authoring to commence, a client needs to first discover the
   capabilities and locations of the available collections.
   Introspection documents are designed to support this discovery
   process.  An Introspection Document describes workspaces, which are
   server-defined groupings of collections.

   Introspection documents are identified with the "application/
   atomserv+xml" media type (see Section 14).

   While an introspection document allows multiple workspaces, there is
   no requirement that a server support multiple workspaces.  In
   addition, a collection MAY appear in more than one workspace.

7.1  Example

   <?xml version="1.0" encoding='utf-8'?>
   <service xmlns="http://purl.org/atom/app#">
     <workspace title="Main Site" >
       <collection
         title="My Blog Entries"
         href="http://example.org/reilly/main" />
       <collection
         title="Pictures"
         href="http://example.org/reilly/pic" >
         <accept>image/*</accept>
       </collection>
     </workspace>
     <workspace title="Side Bar Blog">
       <collection title="Remaindered Links"
         href="http://example.org/reilly/list" />
     </workspace>
   </service>

   This Introspection Document describes two workspaces.  The first,
   called "Main Site", has two collections called "My Blog Entries" and
   "Pictures" whose IRIs are "http://example.org/reilly/main" and
   "http://example.org/reilly/pic" respectively.  The "Pictures"
   includes an accept element indicating that client can post image
   files to the collection to create new entries.  Entries with
   associated media resources are discussed in section 8.3.

   The second workspace is called "Side Bar Blog" and has a single
   collection called "Remaindered Links" whose collection IRI is
   "http://example.org/reilly/list".





Gregorio & de hOra      Expires December 25, 2006              [Page 13]


Internet-Draft        The Atom Publishing Protocol             June 2006


7.2  Element Definitions

7.2.1  The "app:service" Element

   The root of an introspection document is the "app:service" element.

   The "app:service" element is the container for introspection
   information associated with one or more workspaces.  An app:service
   element MUST contain one or more app:workspace elements.


   namespace app = "http://purl.org/atom/app#"
   start = appService


   appService =
      element app:service {
         appCommonAttributes,
         ( appWorkspace+
           & extensionElement* )
      }


7.2.2  The "app:workspace" Element

   The "app:workspace" element contains information elements about the
   collections of resources available for editing.  The app:workspace
   element MAY contain zero or more app:collection elements.


   appWorkspace =
      element app:workspace {
         appCommonAttributes,
         attribute title { text },
         ( appCollection+
           & extensionElement* )
      }


   In an app:workspace element, the first app:collection element MUST
   refer to the preferred or primary collection.  In the following
   example, the "Entries" collection would be considered the preferred
   collection:








Gregorio & de hOra      Expires December 25, 2006              [Page 14]


Internet-Draft        The Atom Publishing Protocol             June 2006


       <service xmlns="http://purl.org/atom/app#">
         <workspace title="My Blog">
           <collection title="Entries"
                href="http://example.org/myblog/entries" />
           <collection title="Photos"
                href="http://example.org/myblog/fotes">
              <accept>image/*</accept>
           </collection>
         </workspace>
       </service>

7.2.2.1  The "title" Attribute

   The app:workspace element MUST contain a "title" attribute, which
   gives a human-readable name for the workspace.  This attribute is
   Language-Sensitive.

7.2.3  The "app:collection" Element

   The "app:collection" describes an Atom Protocol collection.  One
   child element is defined here for app:collection: "app:accept".


   appCollection =
      element app:collection {
         appCommonAttributes,
         attribute title { text },
         attribute href { atomUri  },
         ( appAccept?
           & extensionElement* )
      }


   In an Atom feed, the app:collection element MAY appear as a child of
   an atom:feed or atom:source element to identify the collection to
   which new entries can be added to the feed.

7.2.3.1  The "title" Attribute

   The app:collection element MUST contain a "title" attribute, whose
   value gives a human-readable name for the collection.  This attribute
   is Language-Sensitive.

7.2.3.2  The "href" Attribute

   The app:collection element MUST contain a "href" attribute, whose
   value gives the IRI of the collection.




Gregorio & de hOra      Expires December 25, 2006              [Page 15]


Internet-Draft        The Atom Publishing Protocol             June 2006


7.2.4  The "app:accept" Element

   The app:collection element MAY contain one "app:accept" element.  The
   app:accept element value specifies a comma-separated list of media-
   ranges [RFC2616] identifying the types of representations that can be
   POSTed to the Collection's URI.  Whitespace separating the media-
   range values is considered insignificant and MUST be ignored.

   The app:accept element is similar to the HTTP Accept request-header
   [RFC2616] with the exception that app:accept has no notion of
   preference.  Accordingly, the value syntax of app:accept does not use
   accept-params or "q" parameters as specified in [RFC2616], section
   14.1.  The order of media-ranges is not significant.  The following
   lists are all equivalent:


     <app:accept>image/png, image/*</app:accept>
     <app:accept>image/*, image/png</app:accept>
     <app:accept>image/*</app:accept>

   A value of "entry" indicates that Atom Entry Documents can be posted
   to the Collection.  If the accept element is omitted, or empty,
   clients SHOULD assume that only Atom Entry documents will be accepted
   by the collection.


   appAccept =
      element app:accept {
            appCommonAttributes,
            ( appTypeValue? )
      }

   appTypeValue = ( "entry" | media-type |entry-or-media-type  )
   media-type = xsd:string { pattern = "entry,(.+/.+,?)*" }
   entry-or-media-type = xsd:string { pattern = "(.+/.+,?)*" }
















Gregorio & de hOra      Expires December 25, 2006              [Page 16]


Internet-Draft        The Atom Publishing Protocol             June 2006


8.  Collections

8.1  Creating resources with POST

   To add members to a collection, clients send POST requests to the
   collection's URI.  Collections MAY impose constraints on the media-
   types of request entities POSTed to the collection and MAY generate a
   response with a status code of 415 ("Unsupported Media Type").

   If an entry was created in the collection which received the POST,
   its URI MUST be returned in an HTTP Location header.

   When the server generates a response with a status code of 201
   ("Created"), it SHOULD also return a response body, which, if
   provided, MUST be an Atom Entry Document representing the newly-
   created resource.  Clients MUST NOT assume that an Atom Entry
   returned is a full representation of the member resource.

   Since the server is free to alter the posted entry, for example by
   changing the content of the "id" element. returning the entry as
   described in the previous paragraph can be useful to the client,
   enabling it to correlate the client and server views of the new
   entry.

   When the POST request contains an Atom Entry Document, the response
   from the server SHOULD contain a Content-Location header that
   contains the same character-by-character value as the Location
   header.

   Clients MUST NOT assume that the URI provided by the Location header
   can be used to edit the created entry.

   The request body of the POST need not be an Atom entry.  For example,
   it might be a picture, or a movie.  For a discussion of the issues in
   posting such content, see Section 8.4.

8.2  Example

   Below, the client sends a POST request containing an Atom Entry
   representation to the URI of the Collection:











Gregorio & de hOra      Expires December 25, 2006              [Page 17]


Internet-Draft        The Atom Publishing Protocol             June 2006


       POST /myblog/entries HTTP/1.1
       Host: example.org
       User- Agent: Thingio/1.0
       Content- Type: application/atom+xml
       Content- Length: nnn

       <?xml version="1.0" ?>
       <entry xmlns="http://www.w3.org/2005/Atom">
         <title>Atom-Powered Robots Run Amok</title>
         <id>urn:uuid:1225c695-cfb8-4ebb-aaaa-80da344efa6a</id>
         <updated>2003-12-13T18:30:02Z</updated>
         <author><name>John Doe</name></author>
         <content>Some text.</content>
       </entry>


   The server signals a successful creation with a status code of 201.
   The response includes a "Location" header indicating the URI of the
   Atom Entry and a representation of that Entry in the body of the
   response.

       HTTP/1.1 201 Created
       Date: Fri, 7 Oct 2005 17:17:11 GMT
       Content- Length: nnn
       Content- Type: application/atom+xml; charset="utf-8"
       Content- Location: http://example.org/edit/first-post.atom
       Location: http://example.org/edit/first-post.atom

       <?xml version="1.0"?>
       <entry xmlns="http://www.w3.org/2005/Atom">
         <title>Atom-Powered Robots Run Amok</title>
         <id>urn:uuid:1225c695-cfb8-4ebb-aaaa-80da344efa6a</id>
         <updated>2003-12-13T18:30:02Z</updated>
         <author><name>John Doe</name></author>
         <content>Some text.</content>
         <link rel="edit"
             href="http://example.org/edit/first-post.atom"/>
       </entry>


   Note that the Entry created by the server might not match exactly the
   Entry POSTed by the client.  In particular, a server MAY change the
   values of various elements in the Entry such as the atom:id, atom:
   updated and atom:author values and MAY choose to remove or add other
   elements and attributes, or change element and attribute values.

   In particular, the publishing system in this example filled in some
   values not provided in the original POST.  For example, presumably it



Gregorio & de hOra      Expires December 25, 2006              [Page 18]


Internet-Draft        The Atom Publishing Protocol             June 2006


   ascertained the author's name via the authentication protocol used to
   establish the right to post.

8.3  The 'edit' Link

   Each member Entry within a collection SHOULD contain an atom:link
   element with a link relation of "edit" that contains the IRI used to
   retrieve, update or delete the member Entry.

8.4  Media Resources and Media Link Entries

   As discussed above, if the body of a client's POST is an Atom Entry
   document, this constitutes a request that the server create a new
   entry in the collection to which the POST is addressed and return its
   URI.

   If the body of the client's POST is of a media type other than
   application/atom+xml, this constitutes a request that the server
   create a new resource as represented by the body of the post, called
   a "media resource", and also an entry in the collection to which the
   POST was addressed, called a "media link entry", and return both
   URIs.  If the server successfully creates a media resource and media
   link entry pair, the Location header included in the response MUST be
   that of the media link entry.  The media link entry MUST have a
   "content" element with a "src" attribute which links to the media
   resource.

   The intent is that the media link entry be used to store metadata
   about the (perhaps non-textual) media resource, so that the media and
   the metadata can be retrieved and updated separately.

   A media link entry SHOULD contain an atom:link element with a link
   relation of "edit-media" that contains the IRI used to modify the
   media resource.  Deletion of a media link entry SHOULD result in the
   deletion of the linked media resource.

   Implementors will note that per the requirements of [RFC4287], media
   link entries MUST contain an atom:summary element.  Upon successful
   creation of a media link entry, a server MAY choose to populate the
   atom:summary element (as well as other required elements such as
   atom:id, atom:author and atom:title) with content derived from the
   POSTed media resource or from any other source.  A server might not
   allow a client to modify the server selected values for these
   elements.

   Note that this specification covers the cases when the POST body is
   an Atom Entry, and when it is of a non-Atom media type.  It does not
   specify any request semantics or server behavior in the case where



Gregorio & de hOra      Expires December 25, 2006              [Page 19]


Internet-Draft        The Atom Publishing Protocol             June 2006


   the POST media-type is application/atom+xml but the body is something
   other than an Atom Entry.

8.4.1  Title: Header

   A POST whose body is not of the Atom media type and which thus
   requests the creation of a media resource SHOULD contain a Title:
   header indicating the client's suggested title for the resource.  For
   example:


       POST /myblog/fotes HTTP/1.1
       Host: example.org
       Content- Type: image/png
       Content- Length: nnnn
       Title: An Atom-Powered Robot

       ...binary data...

   The server MAY use the content of the Title: header, as provided or
   in a modified form, in constructing a title for the resource, which
   would presumably appear in the media link entry.


       Title = "Title" ":" [TEXT]

   The syntax of this header MUST conform to the augmented BNF grammar
   in section 2.1 of the HTTP/1.1 specification [RFC2616].  The [TEXT]
   rule is described in section 2.2 of the same document.  Words of
   *TEXT MAY contain characters from character sets other than
   [ISO88591] only when encoded according to the rules of [RFC2047].

8.4.2  Example

   Below, the client sends a POST request containing a PNG image to the
   URI of the Collection:


       POST /myblog/entries HTTP/1.1
       Host: example.org
       Content- Type: image/png
       Content- Length: nnn
       Title: A picture of the beach

       ...binary data...

   The server signals a successful creation with a status code of 201.
   The response includes a "Location" header indicating the URI of the



Gregorio & de hOra      Expires December 25, 2006              [Page 20]


Internet-Draft        The Atom Publishing Protocol             June 2006


   media link entry and a representation of that entry in the body of
   the response.  The media link entry includes a content element with a
   src attribute referencing the media resource, and a link using the
   link relation "edit-media" specifying the IRI to be used for
   modifying the media resource.


       HTTP/1.1 201 Created
       Date: Fri, 7 Oct 2005 17:17:11 GMT
       Content- Length: nnn
       Content- Type: application/atom+xml; charset="utf-8"
       Content- Location: http://example.org/edit/first-post.atom
       Location: http://example.org/edit/first-post.atom

       <?xml version="1.0"?>
       <entry xmlns="http://www.w3.org/2005/Atom">
         <title>A picture of the beach</title>
         <id>urn:uuid:1225c695-cfb8-4ebb-aaaa-80da344efa6a</id>
         <updated>2003-12-13T18:30:02Z</updated>
         <author><name>John Doe</name></author>
         <summary type="text" />
         <content type="image/png"
           src="http://example.org/media/img123.png"/>
         <link rel="edit"
           href="http://example.org/edit/first-post.atom" />
         <link rel="edit-media"
           href="http://example.org/edit/img123.png" />
       </entry>

8.5  Editing Entries with Foreign Markup

   To avoid unintentional loss of data when editing entries or media
   link entries, Atom Protocol clients SHOULD preserve all metadata,
   including unknown foreign markup as defined in Section 6 of
   [RFC4287], which has not been intentionally modified.
















Gregorio & de hOra      Expires December 25, 2006              [Page 21]


Internet-Draft        The Atom Publishing Protocol             June 2006


9.  Listing Collections

   Collection resources MUST provide representations in the form of Atom
   Feed documents whose entries represent the collection's members.
   Each entry in the Feed Document SHOULD have an atom:link element with
   a relation of "edit" (See Section 10.1).

   The entries in the returned Atom Feed MUST be ordered by their "atom:
   updated" property, with the most recently updated entries coming
   first in the document order.  Clients SHOULD be constructed in
   consideration of the fact that changes which do not alter the entry's
   atom:updated value will not affect the position of the entry in a
   collection.

   Clients MUST NOT assume that an Atom Entry returned in the Feed is a
   full representation of a member resource and SHOULD perform a GET on
   the member resource before editing.

   Collections can contain large numbers of resources.  A naive client
   such as a web spider or web browser could be overwhelmed if the
   response to a GET contained every entry in the collection, and the
   server would waste large amounts of bandwidth and processing time on
   clients unable to handle the response.  For this reason, servers MAY
   return a partial listing containing the most recently updated member
   resources.  Such partial feed documents MUST have an atom:link with a
   "next" relation whose "href" value is the URI of the next partial
   listing of the collection (the least recently updated member
   resources) where it exists.  This is called "collection paging".

9.1  Collection Paging

   The returned Atom feed MAY NOT contain entries for all the
   collection's members.  Instead, the Atom feed document MAY contain
   link elements with "rel" attribute values of "next", "previous",
   "first" and "last" that can be used to navigate through the complete
   set of matching entries.

   For instance, suppose a client is supplied the URI
   "http://example.org/entries/go" of a collection of member entries,
   where the server as a matter of policy avoids generating feed
   documents containing more than 10 entries.  The Atom feed document
   for the collection will then represent the first 'page' in a set of
   10 linked feed documents.  The "first" relation will reference the
   initial feed document in the set and the "last" relation references
   the final feed document in the set.  Within each document, the "next"
   and "previous" link relations reference the preceding and subsequent
   documents.




Gregorio & de hOra      Expires December 25, 2006              [Page 22]


Internet-Draft        The Atom Publishing Protocol             June 2006


     <feed xmlns="http://www.w3.org/2005/Atom">
       <link rel="first"
             href="http://example.org/entries/go" />
       <link rel="next"
             href="http://example.org/entries/2" />
       <link rel="last"
             href="http://example.org/entries/10" />
       ...
     </feed>

   The "next" and "previous" link elements for the feed 'page' located
   at "http://example.org/entries/2" would look like this:

     <feed xmlns="http://www.w3.org/2005/Atom">
       <link rel="first"
             href="http://example.org/entries/go" />
       <link rel="previous"
             href="http://example.org/entries/go" />
       <link rel="next"
             href="http://example.org/entries/3" />
       <link rel="last"
             href="http://example.org/entries/10" />
       ...
     </feed>



























Gregorio & de hOra      Expires December 25, 2006              [Page 23]


Internet-Draft        The Atom Publishing Protocol             June 2006


10.  Atom Format Link Relation Extensions

10.1  The "edit" Link Relation

   The Atom Protocol adds the value "edit" to the Atom Registry of Link
   Relations (see section 7.1 of [RFC4287]).  The value of "edit"
   specifies that the value of the href attribute is the IRI of an
   editable Atom Entry Document.  When appearing within an atom:entry,
   the href IRI MAY be used to update and delete the resource
   represented by that entry.  An atom:entry MUST contain no more than
   one "edit" link relation.

10.2  The "edit-media" Link Relation

   The Atom Protocol adds the value "edit-media" to the Atom Registry of
   Link Relations (see section 7.1 of [RFC4287]).  When appearing within
   an atom:entry, the value of the href attribute is an IRI that MAY be
   used to modify a media resource associated with that entry.

   An atom:entry MAY contain zero or more "edit-media" link relations.
   An atom:entry MUST NOT contain more than one atom:link element with a
   rel attribute value of "edit-media" that has the same type and
   hreflang attribute values.  All "edit-media" link relations in the
   same entry reference the same resource.  If a client encounters
   multiple "edit-media" link relations in an entry then it SHOULD
   choose a link based on the client preferences for type and hreflang.
   If a client encounters multiple "edit-media" link relations in an
   entry and has no preference based on the type and hreflang attributes
   then the client SHOULD pick the first "edit-media" link relation in
   document order.





















Gregorio & de hOra      Expires December 25, 2006              [Page 24]


Internet-Draft        The Atom Publishing Protocol             June 2006


11.  Atom Publishing Control Extensions

11.1  The Atom Publishing Control Namespace

   This specification defines an Atom Format extension for publishing
   control called Atom Publishing Control.  The namespace name for the
   Atom Publishing Control's XML vocabulary is
   "http://example.net/appns/".  This specification uses "pub:" for the
   namespace prefix.  The choice of namespace prefix is not semantically
   significant.

11.2  The "pub:control" Element

   namespace pub = "http://example.net/appns/"

    pubControl =
       element pub:control {
       atomCommonAttributes,
       pubDraft?
       & extensionElement
    }

    pubDraft =
      element pub:draft { "yes" | "no" }

   The "pub:control" element MAY appear as a child of an "atom:entry"
   which is being created or updated via the Atom Publishing Protocol.
   The "pub:control" element, if it does appear in an entry, MUST only
   appear at most one time.  The "pub:control" element is considered
   foreign markup as defined in Section 6 of [RFC4287].

   The "pub:control" element and its child elements MAY be included in
   Atom Feed or Entry Documents.

   The "pub:control" element MAY contain exactly one "pub:draft" element
   as defined here, and MAY contain zero or more extension elements as
   outlined in Section 6 of  [RFC4287].  Both clients and servers MUST
   ignore foreign markup present in the pub:control element.

11.2.1  The "pub:draft" Element

   The number of "pub:draft" elements in "pub:control" MUST be zero or
   one.  Its value MUST be one of "yes" or "no".  A value of "no" means
   that the entry MAY be made publicly visible.  If the "pub:draft"
   element is missing then the value MUST be understood to be "no".  The
   inclusion of the pub:draft element represents a request by the client
   to control the visibility of an entry and the pub:draft element MAY
   be ignored by the server.



Gregorio & de hOra      Expires December 25, 2006              [Page 25]


Internet-Draft        The Atom Publishing Protocol             June 2006


12.  Securing the Atom Protocol

   All instances of publishing Atom Format entries SHOULD be protected
   by authentication to prevent posting or editing by unknown sources.
   [[anchor22: note: this section is currently under discussion.]]














































Gregorio & de hOra      Expires December 25, 2006              [Page 26]


Internet-Draft        The Atom Publishing Protocol             June 2006


13.  Security Considerations

   The security of the Atom Protocol is based on [[anchor24: note:
   refers to incomplete section]].

   [[anchor25: note: talk here about denial of service attacks using
   large XML files, or the billion laughs DTD attack.]]












































Gregorio & de hOra      Expires December 25, 2006              [Page 27]


Internet-Draft        The Atom Publishing Protocol             June 2006


14.  IANA Considerations

   An Atom Publishing Protocol Introspection Document, when serialized
   as XML 1.0, can be identified with the following media type:

   MIME media type name: application

   MIME subtype name: atomserv+xml

   Mandatory parameters: None.

   Optional parameters:

      "charset": This parameter has identical semantics to the charset
         parameter of the "application/xml" media type as specified in
         [RFC3023].

   Encoding considerations: Identical to those of "application/xml" as
      described in [RFC3023], section 3.2.

   Security considerations: As defined in this specification.
      [[anchor26: update upon publication]]

      In addition, as this media type uses the "+xml" convention, it
      shares the same security considerations as described in [RFC3023],
      section 10.

   Interoperability considerations: There are no known interoperability
      issues.

   Published specification: This specification. [[anchor27: update upon
      publication]]

   Applications that use this media type: No known applications
      currently use this media type.

   Additional information:

   Magic number(s): As specified for "application/xml" in [RFC3023],
      section 3.2.

   File extension: .atomsrv

   Fragment identifiers: As specified for "application/xml" in
      [RFC3023], section 5.






Gregorio & de hOra      Expires December 25, 2006              [Page 28]


Internet-Draft        The Atom Publishing Protocol             June 2006


   Base URI: As specified in [RFC3023], section 6.

   Macintosh File Type code: TEXT

   Person and email address to contact for further information: Joe
      Gregorio <joe@bitworking.org>

   Intended usage: COMMON

   Author/Change controller: This specification's author(s). [[anchor28:
      update upon publication]]








































Gregorio & de hOra      Expires December 25, 2006              [Page 29]


Internet-Draft        The Atom Publishing Protocol             June 2006


15.  References

15.1  Normative References

   [ISO88591]
              ISO, "International Standard -- Information Processing --
              8-bit Single-Byte Coded Graphic Character Sets -- Part 1:
              Latin alphabet No. 1,", January 1987.

   [RFC2047]  Moore, K., "MIME (Multipurpose Internet Mail Extensions)
              Part Three: Message Header Extensions for Non-ASCII Text",
              RFC 2047, November 1996.

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119, March 1997.

   [RFC2616]  Fielding, R., Gettys, J., Mogul, J., Frystyk, H.,
              Masinter, L., Leach, P., and T. Berners-Lee, "Hypertext
              Transfer Protocol -- HTTP/1.1", RFC 2616, June 1999.

   [RFC3023]  Murata, M., St. Laurent, S., and D. Kohn, "XML Media
              Types", RFC 3023, January 2001.

   [RFC3986]  Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform
              Resource Identifier (URI): Generic Syntax", STD 66,
              RFC 3986, January 2005.

   [RFC3987]  Duerst, M. and M. Suignard, "Internationalized Resource
              Identifiers (IRIs)", RFC 3987, January 2005.

   [RFC4287]  Nottingham, M. and R. Sayre, "The Atom Syndication
              Format", RFC 4287, December 2005.

   [W3C.REC-xml-20040204]
              Yergeau, F., Paoli, J., Sperberg-McQueen, C., Bray, T.,
              and E. Maler, "Extensible Markup Language (XML) 1.0 (Third
              Edition)", W3C REC REC-xml-20040204, February 2004.

   [W3C.REC-xml-infoset-20040204]
              Cowan, J., Tobin, R., and A. Layman, "XML Information Set
              (Second Edition)", W3C REC W3C.REC-xml-infoset-20040204,
              February 2004.

   [W3C.REC-xml-names-19990114]
              Hollander, D., Bray, T., and A. Layman, "Namespaces in
              XML", W3C REC REC-xml-names-19990114, January 1999.

   [W3C.REC-xmlbase-20010627]



Gregorio & de hOra      Expires December 25, 2006              [Page 30]


Internet-Draft        The Atom Publishing Protocol             June 2006


              Marsh, J., "XML Base", W3C REC W3C.REC-xmlbase-20010627,
              June 2001.

15.2  Informative References

   [RNC]      Clark, J., "RELAX NG Compact Syntax", December 2001.

   [W3C.REC-webarch-20041215]
              Walsh, N. and I. Jacobs, "Architecture of the World Wide
              Web, Volume One", W3C REC REC-webarch-20041215,
              December 2004.








































Gregorio & de hOra      Expires December 25, 2006              [Page 31]


Internet-Draft        The Atom Publishing Protocol             June 2006


URIs

   [1]  <http://www.imc.org/atom-protocol/index.html>


Authors' Addresses

   Joe Gregorio (editor)
   BitWorking, Inc
   1002 Heathwood Dairy Rd.
   Apex, NC  27502
   US

   Phone: +1 919 272 3764
   Email: joe@bitworking.com
   URI:   http://bitworking.com/


   Bill de hOra (editor)
   Propylon Ltd.
   45 Blackbourne Square, Rathfarnham Gate
   Dublin, Dublin  D14
   IE

   Phone: +353-1-4927444
   Email: bill.dehora@propylon.com
   URI:   http://www.propylon.com/
























Gregorio & de hOra      Expires December 25, 2006              [Page 32]


Internet-Draft        The Atom Publishing Protocol             June 2006


Appendix A.  Contributors

   The content and concepts within are a product of the Atom community
   and the Atompub Working Group.















































Gregorio & de hOra      Expires December 25, 2006              [Page 33]


Internet-Draft        The Atom Publishing Protocol             June 2006


Appendix B.  RELAX NG Compact Schema

   This appendix is informative.

   The Relax NG schema explicitly excludes elements in the Atom Protocol
   namespace which are not defined in this revision of the
   specification.  Requirements for Atom Protocol processors
   encountering such markup are given in Section 6.2 and Section 6.3 of
   [RFC4287].

   # -*- rnc -*-
   # RELAX NG Compact Syntax Grammar for the Atom Protocol

   namespace app = "http://purl.org/atom/app#"
   namespace local = ""

   start = appService

   # common:attrs

   appCommonAttributes =
      attribute xml:base { atomUri }?,
      attribute xml:lang { atomLanguageTag }?,
      undefinedAttribute*

   undefinedAttribute =
     attribute * - (xml:base | xml:lang | local:*) { text }

   atomUri = text

   atomLanguageTag = xsd:string {
      pattern = "[A-Za-z]{1,8}(-[A-Za-z0-9]{1,8})*"
   }

   # app:service

   appService =
      element app:service {
         appCommonAttributes,
         ( appWorkspace+
           & extensionElement* )
      }

   # app:workspace

   appWorkspace =
      element app:workspace {
         appCommonAttributes,



Gregorio & de hOra      Expires December 25, 2006              [Page 34]


Internet-Draft        The Atom Publishing Protocol             June 2006


         attribute title { text },
         ( appCollection+
           & extensionElement* )
      }

   # app:collection

   appCollection =
      element app:collection {
         appCommonAttributes,
         attribute title { text },
         attribute href { atomUri  },
         ( appAccept?
           & extensionElement* )
      }


   # app:member

   appAccept =
      element app:accept {
            appCommonAttributes,
            ( appTypeValue? )
      }

   appTypeValue = ( "entry" | media-type |entry-or-media-type  )
   media-type = xsd:string { pattern = "entry,(.+/.+,?)*" }
   entry-or-media-type = xsd:string { pattern = "(.+/.+,?)*" }
   # above is an approximation, rnc doesn't support interleaved text

   # Simple Extension

   simpleExtensionElement =
      element * - app:* {
         text
      }

   # Structured Extension

   structuredExtensionElement =
      element * - app:* {
         (attribute * { text }+,
            (text|anyElement)*)
       | (attribute * { text }*,
          (text?, anyElement+, (text|anyElement)*))
      }

   # Other Extensibility



Gregorio & de hOra      Expires December 25, 2006              [Page 35]


Internet-Draft        The Atom Publishing Protocol             June 2006


   extensionElement =
      simpleExtensionElement | structuredExtensionElement



   # Extensions

   anyElement =
      element * {
         (attribute * { text }
          | text
          | anyElement)*
      }

   # EOF




































Gregorio & de hOra      Expires December 25, 2006              [Page 36]


Internet-Draft        The Atom Publishing Protocol             June 2006


Appendix C.  Revision History

   draft-ietf-atompub-protocol-09: PaceWorkspaceMayHaveCollections,
   PaceMediaEntries5,
   http://www.imc.org/atom-protocol/mail-archive/msg05322.html, and
   http://www.imc.org/atom-protocol/mail-archive/msg05272.html

   draft-ietf-atompub-protocol-08: added infoset ref; added wording re
   IRI/URI; fixed URI/IRI ; next/previous fixed as per Atom
   LinkRelations Attribute
   (http://www.imc.org/atom-protocol/mail-archive/msg04095.html);
   incorporated: PaceEditLinkMustToMay; PaceMissingDraftHasNoMeaning,
   PaceRemoveMemberTypeMust, PaceRemoveMemberTypePostMust,
   PaceTitleHeaderOnlyInMediaCollections, PacePreserveForeignMarkup,
   PaceClarifyTitleHeader, PaceClarifyMediaResourceLinks,
   PaceTwoPrimaryCollections;

   draft-ietf-atompub-protocol-07: updated Atom refs to RFC4287;
   incorporated PaceBetterHttpResponseCode;
   PaceClarifyCollectionAndDeleteMethodByWritingLessInsteadOfMore;
   PaceRemoveAcceptPostText; PaceRemoveListTemplate2;
   PaceRemoveRegistry; PaceRemoveWhoWritesWhat;
   PaceSimplifyClarifyBetterfyRemoveBogusValidityText;
   PaceCollectionOrderSignificance; PaceFixLostIntrospectionText;
   PaceListPaging; PaceCollectionControl; element typo in Listing
   collections para3 (was app:member-type, not app:list-template);
   changed post atom entry example to be valid.  Dropped inline use of
   'APP'.  Removed nested diagram from section 4.  Added ed notes in the
   security section.

   draft-ietf-atompub-protocol-06 - Removed: Robert Sayre from the
   contributors section per his request.  Added in
   PaceCollectionControl.  Fixed all the {daterange} verbage and
   examples so they all use a dash.  Added full rnc schema.  Collapsed
   Introspection and Collection documents into a single document.
   Removed {dateRange} queries.  Renamed search to list.  Moved
   discussion of media and entry collection until later in the document
   and tied the discussion to the Introspection element app:member-type.

   draft-ietf-atompub-protocol-05 - Added: Contributors section.  Added:
   de hOra to editors.  Fixed: typos.  Added diagrams and description to
   model section.  Incorporates PaceAppDocuments, PaceAppDocuments2,
   PaceSimplifyCollections2 (large-sized chunks of it anyhow: the
   notions of Entry and Generic resources, the section 4 language on the
   Protocol Model, 4.1 through 4.5.2, the notion of a Collection
   document, as in Section 5 through 5.3, Section 7 "Collection
   resources", Selection resources (modified from pace which talked
   about search); results in major mods to Collection Documents, Section



Gregorio & de hOra      Expires December 25, 2006              [Page 37]


Internet-Draft        The Atom Publishing Protocol             June 2006


   9.2 "Title: Header" and brokeout para to section 9.1 Editing Generic
   Resources).  Added XML namespace and language section.  Some cleanup
   of front matter.  Added Language Sensitivity to some attributes.
   Removed resource descriptions from terminology.  Some juggling of
   sections.  See:
   http://www.imc.org/atom-protocol/mail-archive/msg01812.html.

   draft-ietf-atompub-protocol-04 - Add ladder diagrams, reorganize, add
   SOAP interactions

   draft-ietf-atompub-protocol-03 - Incorporates PaceSliceAndDice3 and
   PaceIntrospection.

   draft-ietf-atompub-protocol-02 - Incorporates Pace409Response,
   PacePostLocationMust, and PaceSimpleResourcePosting.

   draft-ietf-atompub-protocol-01 - Added in sections on Responses for
   the EditURI.  Allow 2xx for response to EditURI PUTs.  Elided all
   mentions of WSSE.  Started adding in some normative references.
   Added the section "Securing the Atom Protocol".  Clarified that it is
   possible that the PostURI and FeedURI could be the same URI.  Cleaned
   up descriptions for Response codes 400 and 500.

   Rev draft-ietf-atompub-protocol-00 - 5Jul2004 - Renamed the file and
   re-titled the document to conform to IETF submission guidelines.
   Changed MIME type to match the one selected for the Atom format.
   Numerous typographical fixes.  We used to have two 'Introduction'
   sections.  One of them was moved into the Abstract the other absorbed
   the Scope section.  IPR and copyright notifications were added.

   Rev 09 - 10Dec2003 - Added the section on SOAP enabled clients and
   servers.

   Rev 08 - 01Dec2003 - Refactored the specification, merging the
   Introspection file into the feed format.  Also dropped the
   distinction between the type of URI used to create new entries and
   the kind used to create comments.  Dropped user preferences.

   Rev 07 - 06Aug2003 - Removed the use of the RSD file for auto-
   discovery.  Changed copyright until a final standards body is chosen.
   Changed query parameters for the search facet to all begin with atom-
   to avoid name collisions.  Updated all the Entries to follow the 0.2
   version.  Changed the format of the search results and template file
   to a pure element based syntax.

   Rev 06 - 24Jul2003 - Moved to PUT for updating Entries.  Changed all
   the mime-types to application/x.atom+xml.  Added template editing.
   Changed 'edit-entry' to 'create-entry' in the Introspection file to



Gregorio & de hOra      Expires December 25, 2006              [Page 38]


Internet-Draft        The Atom Publishing Protocol             June 2006


   more accurately reflect its purpose.

   Rev 05 - 17Jul2003 - Renamed everything Echo into Atom.  Added
   version numbers in the Revision history.  Changed all the mime-types
   to application/atom+xml.

   Rev 04 - 15Jul2003 - Updated the RSD version used from 0.7 to 1.0.
   Change the method of deleting an Entry from POSTing <delete/> to
   using the HTTP DELETE verb.  Also changed the query interface to GET
   instead of POST.  Moved Introspection Discovery to be up under
   Introspection.  Introduced the term 'facet' for the services listed
   in the Introspection file.

   Rev 03 - 10Jul2003 - Added a link to the Wiki near the front of the
   document.  Added a section on finding an Entry.  Retrieving an Entry
   now broken out into its own section.  Changed the HTTP status code
   for a successful editing of an Entry to 205.

   Rev 02 - 7Jul2003 - Entries are no longer returned from POSTs,
   instead they are retrieved via GET.  Cleaned up figure titles, as
   they are rendered poorly in HTML.  All content-types have been
   changed to application/atom+xml.

   Rev 01 - 5Jul2003 - Renamed from EchoAPI.html to follow the more
   commonly used format: draft-gregorio-NN.html.  Renamed all references
   to URL to URI.  Broke out introspection into its own section.  Added
   the Revision History section.  Added more to the warning that the
   example URIs are not normative.























Gregorio & de hOra      Expires December 25, 2006              [Page 39]


Internet-Draft        The Atom Publishing Protocol             June 2006


Intellectual Property Statement

   The IETF takes no position regarding the validity or scope of any
   Intellectual Property Rights 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; nor does it represent that it has
   made any independent effort to identify any such rights.  Information
   on the procedures with respect to rights in RFC documents can be
   found in BCP 78 and BCP 79.

   Copies of IPR disclosures made to the IETF Secretariat 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 on-line IPR repository at
   http://www.ietf.org/ipr.

   The IETF invites any interested party to bring to its attention any
   copyrights, patents or patent applications, or other proprietary
   rights that may cover technology that may be required to implement
   this standard.  Please address the information to the IETF at
   ietf-ipr@ietf.org.

   The IETF has been notified of intellectual property rights claimed in
   regard to some or all of the specification contained in this
   document.  For more information consult the online list of claimed
   rights.


Disclaimer of Validity

   This document and the information contained herein are provided on an
   "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS
   OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET
   ENGINEERING TASK FORCE DISCLAIM 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.


Copyright Statement

   Copyright (C) The Internet Society (2006).  This document is subject
   to the rights, licenses and restrictions contained in BCP 78, and
   except as set forth therein, the authors retain all their rights.





Gregorio & de hOra      Expires December 25, 2006              [Page 40]


Internet-Draft        The Atom Publishing Protocol             June 2006


Acknowledgment

   Funding for the RFC Editor function is currently provided by the
   Internet Society.















































Gregorio & de hOra      Expires December 25, 2006              [Page 41]