The Atom Publishing Protocol

Atom Protocol documents allow the use of IRIs [RFC3987] as well as URIs [RFC3986] to identify Resources. Before an IRI in a document is used by HTTP, the IRI is first converted to a URI according to the procedure defined in Section 3.1 of [RFC3987]. In accordance with that specification, the conversion SHOULD be applied as late as possible. Conversion does not imply Resource creation -- the IRI and the URI into which it is converted identify the same Resource.¶

While the Atom Protocol specifies the formats of the representations that are exchanged and the actions that can be performed on the IRIs embedded in those representations, it does not constrain the form of the URIs that are used. HTTP [RFC2616] specifies that the URI space of each server is controlled by that server, and this protocol imposes no further constraints on that control.¶

The Atom Protocol does not make a distinction between Feeds used for Collections and other Atom Feeds. The only mechanism that this specification supplies for indicating that a Feed is a Collection Feed is the presence of the Feed's IRI in a Service Document.¶

• GET is used to retrieve a representation of a known Resource.
• POST is used to create a new, dynamically named, Resource. When the client submits non-Atom-Entry representations to a Collection for creation, two Resources are always created -- a Media Entry for the requested Resource, and a Media Link Entry for metadata about the Resource that will appear in the Collection.
• PUT is used to edit a known Resource. It is not used for Resource creation.
• DELETE is used to remove a known Resource.

The Atom Protocol only covers the creating, editing, and deleting of Entry and Media Resources. Other Resources could be created, edited, and deleted as the result of manipulating a Collection, but the number of those Resources, their media types, and effects of Atom Protocol operations on them are outside the scope of this specification.¶

Since all aspects of client-server interaction are defined in terms of HTTP, [RFC2616] should be consulted for any areas not covered in this specification.¶

The Atom Protocol imposes few restrictions on the actions of servers. Unless a constraint is specified here, servers can be expected to vary in behavior, in particular around the manipulation of Atom Entries sent by clients. For example, although this specification only defines the expected behavior of Collections with respect to GET and POST, this does not imply that PUT, DELETE, PROPPATCH, and others are forbidden on Collection Resources -- only that this specification does not define what the server's response would be to those methods. Similarly, while some HTTP status codes are mentioned explicitly, clients ought to be prepared to handle any status code from a server. Servers can choose to accept, reject, delay, moderate, censor, reformat, translate, relocate, or re-categorize the content submitted to them. Only some of these choices are immediately relayed back to the client in responses to client requests; other choices may only become apparent later, in the feed or published entries. The same series of requests to two different publishing sites can result in a different series of HTTP responses, different resulting feeds, or different entry contents.¶

As a result, client software has to be written flexibly to accept what the server decides are the results of its submissions. Any server response or server content modification not explicitly forbidden by this specification or HTTP [RFC2616] is therefore allowed.¶

1. The client sends a GET request to the URI of the Service Document.
2. The server responds with a Service Document enumerating the IRIs of a group 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.

To list the Members of a Collection, the client sends a GET request to the URI of a Collection. An Atom Feed Document is returned whose Entries contain the IRIs of Member Resources. The returned Feed may describe all, or only a partial list, of the Members in a Collection (see Section 10).¶

1. The client sends a GET request to the URI of the Collection.
2. The server responds with an Atom Feed Document containing the IRIs of the Collection Members.

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 IRI of the newly created Entry Resource. Media Resources could have also been created and their IRIs can be found through the Entry Resource. See Section 9.6 for more details.

Once a Resource has been created and its Member URI is known, that URI can be used to retrieve, edit, and delete the Resource. Section 11 describes extensions to the Atom Syndication Format used in the Atom Protocol for editing purposes.¶

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. Implementers are asked to note that according to the HTTP specification, HTTP 4xx and 5xx response entities SHOULD include a human-readable explanation of the error.¶

This specification defines two kinds of documents -- Category Documents and Service Documents.¶

A Category Document (Section 7) contains lists of categories specified using the "atom:category" element from the Atom Syndication Format (see Section 4.2.2 of [RFC4287]).¶

A Service Document (Section 8) groups available Collections into Workspaces.¶

Atom Publishing Protocol XML Documents MUST be "namespace-well-formed" as specified in Section 7 of [REC-xml-names].¶

This specification uses the prefix "app:" for the namespace name. The prefix "atom:" is used for "http://www.w3.org/2005/Atom", the namespace name of the Atom Syndication Format [RFC4287]. These namespace prefixes are not semantically significant.¶

This specification does not define any DTDs for Atom Protocol formats, and hence does not require them to be "valid" in the sense used by [REC-xml].¶

Unrecognized markup in an Atom Publishing Protocol document is considered "foreign markup" as defined in Section 6 of the Atom Syndication Format [RFC4287]. Foreign markup can be used anywhere within a Category or Service Document unless it is explicitly forbidden. Processors that encounter foreign markup MUST NOT stop processing and MUST NOT signal an error. Clients SHOULD preserve foreign markup when transmitting such documents.¶

The namespace name "http://www.w3.org/2007/app" is reserved for forward-compatible revisions of the Category and Service Document types. This does not exclude the addition of elements and attributes that might not be recognized by processors conformant to this specification. Such unrecognized markup from the "http://www.w3.org/2007/app" namespace MUST be treated as foreign markup.¶

A Service Document groups Collections into Workspaces. Operations on Workspaces, such as creation or deletion, are not defined by this specification. This specification assigns no meaning to Workspaces; that is, a Workspace does not imply any specific processing assumptions.¶

There is no requirement that a server support multiple Workspaces. In addition, a Collection MAY appear in more than one Workspace.¶

The Service Document above describes two Workspaces. The first Workspace is called "Main Site", and has two Collections called "My Blog Entries" and "Pictures", whose IRIs are "http://example.org/blog/main" and "http://example.org/blog/pic" respectively. The "Pictures" Collection includes three "accept" elements indicating the types of image files the client can send to the Collection to create new Media Resources (entries associated with Media Resources are discussed in Section 9.6).¶

The second Workspace is called "Sidebar Blog" and has a single Collection called "Remaindered Links" whose IRI is "http://example.org/sidebar/list". The Collection has an "accept" element whose content is "application/atom+xml;type=entry", indicating it will accept Atom Entries from a client.¶

Within each of the two Entry Collections, the "categories" element provides a list of available categories for Member Entries. In the "My Blog Entries" Collection, the list of available categories is available through the "href" attribute. The "Sidebar Blog" Collection provides a category list within the Service Document, but states the list is fixed, signaling a request from the server that Entries be POSTed using only those two categories.¶

The Member URI allows clients to retrieve, edit, and delete a Member Resource using HTTP's GET, PUT, and DELETE methods. Entry Resources are represented as Atom Entry documents.¶

Member URIs appear in two places. They are returned in a Location header after successful Resource creation using POST, as described in Section 9.2 below. They can also appear in a Collection Feed's Entries, as atom:link elements with a link relation of "edit".¶

A Member Entry SHOULD contain such an atom:link element with a link relation of "edit", which indicates the Member URI.¶

To add members to a Collection, clients send POST requests to the URI of the Collection.¶

Successful member creation is indicated with a 201 ("Created") response code. When the Collection responds with a status code of 201, it SHOULD also return a response body, which MUST be an Atom Entry Document representing the newly created Resource. Since the server is free to alter the POSTed Entry, for example, by changing the content of the atom:id element, returning the Entry can be useful to the client, enabling it to correlate the client and server views of the new Entry.¶

When a Member Resource is created, its Member Entry URI MUST be returned in a Location header in the Collection's response.¶

If the creation request contained an Atom Entry Document, and the subsequent response from the server contains a Content-Location header that matches the Location header character-for-character, then the client is authorized to interpret the response entity as being a complete representation of the newly created Entry. Without a matching Content-Location header, the client MUST NOT assume the returned entity is a complete representation of the created Resource.¶

The request body sent with the POST need not be an Atom Entry. For example, it might be a picture or a movie. Collections MAY return a response with a status code of 415 ("Unsupported Media Type") to indicate that the media type of the POSTed entity is not allowed or supported by the Collection. For a discussion of the issues in creating such content, see Section 9.6.¶

To edit a Member Resource, a client sends a PUT request to its Member URI, as specified in [RFC2616].¶

To avoid unintentional loss of data when editing Member Entries or Media Link Entries, an Atom Protocol client SHOULD preserve all metadata that has not been intentionally modified, including unknown foreign markup as defined in Section 6 of [RFC4287].¶

To delete a Member Resource, a client sends a DELETE request to its Member URI, as specified in [RFC2616]. The deletion of a Media Link Entry SHOULD result in the deletion of the corresponding Media Resource.¶

Implementers are advised to pay attention to cache controls and to make use of the mechanisms available in HTTP when editing Resources, in particular, entity-tags as outlined in [NOTE-detect-lost-update]. Clients are not assured to receive the most recent representations of Collection Members using GET if the server is authorizing intermediaries to cache them.¶

A client can POST Media Resources as well as Entry Resources to a Collection. If a server accepts such a request, then it MUST create two new Resources -- one that corresponds to the entity sent in the request, called the Media Resource, and an associated Member Entry, called the Media Link Entry. Media Link Entries are represented as Atom Entries, and appear in the Collection.¶

The Media Link Entry contains the metadata and IRI of the (perhaps non-textual) Media Resource. The Media Link Entry thus makes the metadata about the Media Resource separately available for retrieval and alteration.¶

The server can signal the media types it will accept using the app:accept element in the Service Document, as specified in Section 8.3.4.¶

Successful responses to creation requests MUST include the URI of the Media Link Entry in the Location header. The Media Link Entry SHOULD contain an atom:link element with a link relation of "edit-media" that contains the Media Resource IRI. The Media Link Entry MUST have an atom:content element with a "src" attribute. The value of the "src" attribute is an IRI for the newly created Media Resource. It is OPTIONAL that the IRI of the "src" attribute on the atom:content element be the same as the Media Resource IRI. For example, the "src" attribute value might instead be a link into a static cache or content distribution network and not the Media Resource IRI.¶

Implementers are asked to note that [RFC4287] specifies that Atom Entries MUST contain an atom:summary element. Thus, upon successful creation of a Media Link Entry, a server MAY choose to populate the atom:summary element (as well as any other mandatory elements such as atom:id, atom:author, and atom:title) with content derived from the POSTed entity or from any other source. A server might not allow a client to modify the server-selected values for these elements.¶

For Resource creation, this specification only defines cases where the POST body has an Atom Entry entity declared as an Atom media type ("application/atom+xml"), or a non-Atom entity declared as a non-Atom media type. When a client is POSTing an Atom Entry to a Collection, it may use a media type of either "application/atom+xml" or "application/atom +xml;type=entry". This specification does not specify any request semantics or server behavior in the case where the POSTed media type is "application/atom+xml" but the body is something other than an Atom Entry. In particular, what happens on POSTing an Atom Feed Document to a Collection using the "application/atom+xml" media type is undefined.¶

The Atom Protocol does not specify a means to create multiple representations of the same Resource (for example, a PNG and a JPG of the same image) either on creation or editing.¶

Slug is an HTTP entity-header whose presence in a POST to a Collection constitutes a request by the client to use the header's value as part of any URIs that would normally be used to retrieve the to-be-created Entry or Media Resources.¶

Servers MAY use the value of the Slug header when creating the Member URI of the newly created Resource, for instance, by using some or all of the words in the value for the last URI segment. Servers MAY also use the value when creating the atom:id, or as the title of a Media Link Entry (see Section 9.6).¶

Servers MAY choose to ignore the Slug entity-header. Servers MAY alter the header value before using it. For instance, a server might filter out some characters or replace accented letters with non-accented ones, replace spaces with underscores, change case, and so on.¶

Collections can contain large numbers of Resources. A client such as a web spider or web browser might be overwhelmed if the response to a GET contained every Entry in a Collection -- in turn the server might also waste bandwidth and processing time on generating a response that cannot be handled. For this reason, servers MAY respond to Collection GET requests with a Feed Document containing a partial list of the Collection's members, and a link to the next partial list feed, if it exists. The first such partial list returned MUST contain the most recently edited member Resources and MUST have an atom:link with a "next" relation whose "href" value is the URI of the next partial list of the Collection. This next partial list will contain the next most recently edited set of Member Resources (and an atom:link to the following partial list if it exists).¶

In addition to the "next" relation, partial list feeds MAY contain link elements with "rel" attribute values of "previous", "first", and "last", that can be used to navigate through the complete set of entries in the Collection.¶

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 partial list of a set of 10 linked Feed Documents. The "first" relation references the initial Feed Document in the set and the "last" relation references the final Feed Document in the set. Within each document, the "previous" and "next" link relations reference the preceding and subsequent documents.¶

  <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 "previous" and "next" link elements for the partial list feed 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>

The "app:edited" element is a Date construct (as defined by [RFC4287]), whose content indicates the last time an Entry was edited. If the entry has not been edited yet, the content indicates the time it was created. Atom Entry elements in Collection Documents SHOULD contain one app:edited element, and MUST NOT contain more than one.¶

The server SHOULD change the value of this element every time an Entry Resource or an associated Media Resource has been edited.¶

This specification 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 Member Entry. When appearing within an atom:entry, the href IRI can be used to retrieve, update, and delete the Resource represented by that Entry. An atom:entry MUST NOT contain more than one "edit" link relation.¶

This specification 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 can be used to modify a Media Resource associated with that Entry.¶

An atom:entry element 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.¶

This specification defines a new "type" parameter for use with the "application/atom+xml" media type. The "type" parameter has a value of "entry" or "feed".¶

Neither the parameter name nor its value are case sensitive.¶

The value "entry" indicates that the media type identifies an Atom Entry Document. The root element of the document MUST be atom:entry.¶

The value "feed" indicates that the media type identifies an Atom Feed Document. The root element of the document MUST be atom:feed.¶

If not specified, the type is assumed to be unspecified, requiring Atom processors to examine the root element to determine the type of Atom document.¶

The "app:control" element MAY appear as a child of an atom:entry that is being created or updated via the Atom Publishing Protocol. The app:control element MUST appear only once in an Entry. The app:control element is considered foreign markup as defined in Section 6 of [RFC4287].¶

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

The app:control element can contain an "app:draft" element as defined below, and it can contain extension elements as defined in Section 6 of [RFC4287].¶

Atom Publishing Protocol server implementations need to take adequate precautions to ensure malicious clients cannot consume excessive server resources (CPU, memory, disk, etc.).¶

Atom Publishing Protocol server implementations are susceptible to replay attacks. Specifically, this specification does not define a means of detecting duplicate requests. Accidentally sent duplicate requests are indistinguishable from intentional and malicious replay attacks.¶

Atom Publishing Protocol implementations are susceptible to a variety of spoofing attacks. Malicious clients might send Atom Entries containing inaccurate information anywhere in the document.¶

Atom Feed and Entry Documents can contain XML External Entities as defined in Section 4.2.2 of [REC-xml]. Atom implementations are not required to load external entities. External entities are subject to the same security concerns as any network operation and can alter the semantics of an Atom document. The same issues exist for Resources linked to by Atom elements such as atom:link and atom:content.¶

Atom Entry and Feed Documents can contain XML Digital Signatures [REC-xmldsig-core] and can be encrypted using XML Encryption [REC-xmlenc-core] as specified in Section 5 of [RFC4287]. Handling of signatures and encrypted elements in Atom documents is discussed in Sections 5 and 6.3 of [RFC4287].¶

Neither servers nor clients are under any obligation to support encryption and digital signature of Entries or Feeds, although it is certainly possible that in some installations, clients or servers might require signing or encrypting of the documents exchanged in the Atom Protocol.¶

Because servers are allowed (and in some cases, expected) to modify the contents of an Entry Document before publishing it, signatures within an entry are only likely to be useful to the server to which the entry is being sent. Clients cannot assume that the signature will be valid when viewed by a third party, or even that the server will publish the client's signature.¶

A server is allowed to strip client-applied signatures, to strip client-applied signatures and then re-sign with its own public key, and to oversign an entry with its own public key. The meaning to a third party of a signature applied by a server is the same as a signature from anyone, as described in [RFC4287]. It is RECOMMENDED that a server that is aware that it has changed any part of an Entry Document that was signed by the client should strip that signature before publishing the entry in order to prevent third parties from trying to interpret a signature that cannot be validated.¶

Atom Publishing Protocol implementations handle URIs and IRIs. See Section 7 of [RFC3986] and Section 8 of [RFC3987] for security considerations related to their handling and use.¶

The Atom Publishing Protocol leaves the server in control of minting URIs. The use of any client-supplied data for creating new URIs is subject to the same concerns as described in the next section.¶

Atom Feed and Entry Documents can contain a broad range of content types including code that might be executable in some contexts. Malicious clients could attempt to attack servers or other clients by injecting code into a Collection Document's Entry or Media Resources.¶

Server implementations are strongly encouraged to verify that client-supplied content is safe prior to accepting, processing, or publishing it. In the case of HTML, experience indicates that verification based on a white list of acceptable content is more effective than a black list of forbidden content.¶

Additional information about XHTML and HTML content safety can be found in Section 8.1 of [RFC4287].¶

MIME media type name:

application

MIME subtype name:

atomcat+xml

Required 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 RFC 5023.

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:

RFC 5023.

Applications that use this media type:

No known applications currently use this media type.

Magic number(s):

As specified for "application/xml" in [RFC3023], Section 3.2.

File extension:

.atomcat

Fragment identifiers:

As specified for "application/xml" in [RFC3023], Section 5.

Base URI:

As specified in [RFC3023], Section 6.

Macintosh file type code:

TEXT

Person & email address to contact for further information:

Joe Gregorio <joe@bitworking.org>

Intended usage:

COMMON

Author/Change controller:

IETF (iesg@ietf.org) Internet Engineering Task Force

MIME media type name:

application

MIME subtype name:

atomsvc+xml

Required 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 RFC 5023.

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:

RFC 5023.

Applications that use this media type:

No known applications currently use this media type.

Magic number(s):

As specified for "application/xml" in [RFC3023], Section 3.2.

File extension:

.atomsvc

Fragment identifiers:

As specified for "application/xml" in [RFC3023], Section 5.

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:

IETF (iesg@ietf.org) Internet Engineering Task Force

Header field name:

SLUG

Applicable protocol:

http [RFC2616]

Status:

standard.

Author/Change controller:

IETF (iesg@ietf.org) Internet Engineering Task Force

Specification document(s):

RFC 5023.

Related information:

None.

Attribute Value:

edit

Description:

An IRI of an editable Member Entry. When appearing within an atom:entry, the href IRI can be used to retrieve, update, and delete the Resource represented by that Entry.

Expected display characteristics:

Undefined; this relation can be used for background processing or to provide extended functionality without displaying its value.

Security considerations:

Automated agents should take care when this relation crosses administrative domains (e.g., the URI has a different authority than the current document).

Attribute Value:

edit-media

Description:

An IRI of an editable Media Resource. When appearing within an atom:entry, the href IRI can be used to retrieve, update, and delete the Media Resource associated with that Entry.

Expected display characteristics:

Undefined; this relation can be used for background processing or to provide extended functionality without displaying its value.

Security considerations:

Automated agents should take care when this relation crosses administrative domains (e.g., the URI has a different authority than the current document).

IANA has added a reference to this specification in the 'application/atom+xml' media type registration.¶

17.1. Normative References

[REC-xml]

Yergeau, F., Paoli, J., Bray, T., Sperberg-McQueen, C., and E. Maler, “Extensible Markup Language (XML) 1.0 (Fourth Edition)”, World Wide Web Consortium Recommendation REC-xml-20060816, August 2006, <http://www.w3.org/TR/2006/REC-xml-20060816>.

[REC-xml-infoset]

Cowan, J. and R. Tobin, “XML Information Set (Second Edition)”, World Wide Web Consortium Recommendation REC-xml-infoset-20040204, February 2004, <http://www.w3.org/TR/2004/REC-xml-infoset-20040204>.

[REC-xml-names]

Hollander, D., Bray, T., Tobin, R., and A. Layman, “Namespaces in XML 1.0 (Second Edition)”, World Wide Web Consortium Recommendation REC-xml-names-20060816, August 2006, <http://www.w3.org/TR/2006/REC-xml-names-20060816>.

[REC-xmlbase]

Marsh, J., “XML Base”, W3C REC W3C.REC-xmlbase-20010627, June 2001, <http://www.w3.org/TR/2001/REC-xmlbase-20010627>.

[REC-xmldsig-core]

Solo, D., Reagle, J., and D. Eastlake, “XML-Signature Syntax and Processing”, World Wide Web Consortium Recommendation REC-xmldsig-core-20020212, February 2002, <http://www.w3.org/TR/2002/REC-xmldsig-core-20020212>.

[REC-xmlenc-core]

Eastlake, D. and J. Reagle, “XML Encryption Syntax and Processing”, World Wide Web Consortium Recommendation REC-xmlenc-core-20021210, December 2002, <http://www.w3.org/TR/2002/REC-xmlenc-core-20021210>.

[RFC2119]

Bradner, S., “Key words for use in RFCs to Indicate Requirement Levels”, BCP 14, RFC 2119, March 1997.

[RFC2246]

Dierks, T. and C. Allen, “The TLS Protocol Version 1.0”, RFC 2246, January 1999.

[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.

[RFC2617]

Franks, J., Hallam-Baker, P., Hostetler, J., Lawrence, S., Leach, P., Luotonen, A., and L. Stewart, “HTTP Authentication: Basic and Digest Access Authentication”, RFC 2617, June 1999.

[RFC2818]

Rescorla, E., “HTTP Over TLS”, RFC 2818, May 2000.

[RFC3023]

Murata, M., St. Laurent, S., and D. Kohn, “XML Media Types”, RFC 3023, January 2001.

[RFC3629]

Yergeau, F., “UTF-8, a transformation format of ISO 10646”, STD 63, RFC 3629, November 2003.

[RFC3864]

Klyne, G., Nottingham, M., and J. Mogul, “Registration Procedures for Message Header Fields”, BCP 90, RFC 3864, September 2004.

[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.

[RFC4288]

Freed, N. and J. Klensin, “Media Type Specifications and Registration Procedures”, BCP 13, RFC 4288, December 2005.

[RFC4346]

Dierks, T. and E. Rescorla, “The Transport Layer Security (TLS) Protocol Version 1.1”, RFC 4346, April 2006.

17.2. Informative References

[NOTE-detect-lost-update]

Nielsen, H. and D. LaLiberte, “Editing the Web: Detecting the Lost Update Problem Using Unreserved Checkout”, World Wide Web Consortium NOTE NOTE-detect-lost-update, May 1999, <http://www.w3.org/1999/04/Editing/>.

[REC-webarch]

Walsh, N. and I. Jacobs, “Architecture of the World Wide Web, Volume One”, W3C REC REC-webarch-20041215, December 2004, <http://www.w3.org/TR/2004/REC-webarch-20041215>.

[RNC]

Clark, J., “RELAX NG Compact Syntax”, December 2001, <http://www.oasis-open.org/committees/relax-ng/compact-20021121.html>.