Network Working Group J. Snell
Internet-Draft August 21, 2007
Intended status: Standards Track
Expires: February 22, 2008
Atom Publishing Protocol Features Extension
draft-snell-atompub-feature-07.txt
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Copyright Notice
Copyright (C) The IETF Trust (2007).
Abstract
This document introduces extensions to the Atom Publishing Protocol
service document format for expressing metadata about the behaviors,
functions and capabilities supported by an Atom Publishing Protocol
collection.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Notational Conventions . . . . . . . . . . . . . . . . . . . . 3
3. The f:feature element . . . . . . . . . . . . . . . . . . . . 4
3.1. Example . . . . . . . . . . . . . . . . . . . . . . . . . 6
3.2. Contradictory Features . . . . . . . . . . . . . . . . . . 6
4. The f:type element . . . . . . . . . . . . . . . . . . . . . . 7
4.1. An example f:feature using the f:type element . . . . . . 7
5. Security Considerations . . . . . . . . . . . . . . . . . . . 7
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 8
6.1. Registry of Atom Publishing Features . . . . . . . . . . . 8
6.1.1. Initial Assignments . . . . . . . . . . . . . . . . . 8
7. Normative References . . . . . . . . . . . . . . . . . . . . . 20
Appendix A. Acknowledgements . . . . . . . . . . . . . . . . . . 21
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 21
Intellectual Property and Copyright Statements . . . . . . . . . . 22
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1. Introduction
This document introduces extensions for the Atom Publishing Protocol
service document format for expressing metadata about the behaviors,
functions and capabilities supported by an Atom Publishing Protocol
collection.
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 BCP 14, [RFC2119].
This specification uses XML Namespaces [W3C.REC-xml-names-19990114]
to uniquely identify XML element names. It uses the following
namespace prefix for the indicated namespace URI;
"f": "http://purl.org/atompub/features/1.0"
This specification uses terms from the XML Infoset
[W3C.REC-xml-infoset-20040204]. However, this specification uses a
shorthand; the phrase "Information Item" is omitted when naming
Element Information Items. Therefore, when this specification uses
the terms "element" and "attribute" it is referring, respectively, to
the Element and Attribute Information Items in Infoset terms.
This specification uses the terms "atomUri" and
"atomCommonAttributes" from the non-normative RELAX NG Compact schema
included in [RFC4287]. Where used, these serve the same purpose and
have the same meaning as their use in [RFC4287].
Atom allows the use of IRIs [RFC3987]. Every URI [RFC3986] is also
an IRI, so a URI may be used wherever below an IRI is named. There
are two special considerations: (1) when an IRI that is not also a
URI is given for dereferencing, it MUST be mapped to a URI using the
steps in Section 3.1 of [RFC3987] and (2) when an IRI is serving as
an identifier, it MUST NOT be so mapped.
Any element 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 [RFC3986],
establishing the base URI (or IRI) for resolving any relative
references found within the effective scope of the xml:base
attribute.
Any element defined by this specification MAY have an xml:lang
attribute, whose content indicates the natural language for the
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element and its descendents. The language context is only
significant for elements and attributes declared to be "Language-
Sensitive". Requirements regarding the content and interpretation of
xml:lang are specified in XML 1.0 [W3C.REC-xml-20040204], Section
2.12.
3. The f:feature element
A feature is an abstract behavior, function and capability supported
by an Atom Publishing Protocol collection. Examples of features that
might be supported by an Atom publishing server include support for
draft entries, scheduled publication of entries, use of a particular
set of Atom format extensions, use of a particular authentication
scheme, and so on. The f:feature element can be used in an app:
collection element to indicate that the collection supports the
feature specified and may require that a client wishing to use the
endpoint use that feature. Features are identified using permanent,
universally unique IRI's.
namespace f = "http://purl.org/atompub/features/1.0"
feature = element f:feature {
atomCommonAttributes,
attribute ref { atomUri },
attribute status { 'supported' | 'required' | 'unsupported'}?,
attribute href { atomUri }?,
attribute label { text }?,
(anyElement)*
}
anyElement = element * - f:* {
(attribute * { text }
| text
| anyElement)*
}
The ref attribute specifies a globally unique IRI identifying a
feature supported by a collection. The value of the ref attribute
MUST be compared on a case-sensitive, character-by-character basis.
Relative references MUST NOT be used.
The status attribute indicates a collections level of support for the
identified feature. The value of the attribute can be "supported",
"required" or "unsupported". If not specified, the value is assumed
to be "supported".
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o The value "supported" indicates that the server supports the
identified feature. Clients MAY utilize the feature when
interacting with the collection.
o The value "required" indicates that server supports the identified
feature. Clients MUST utilize the feature when interacting with
the collection.
o The value "unsupported" indicates that the server explicitly does
not support a feature. Clients SHOULD NOT utilize the feature
when interacting with the collection.
An optional href attribute MAY be used to specify the URI of a human-
readable description of the feature. Relative references MAY be
used.
The optional label attribute MAY be used to specify a human-readable
label for the feature. The value of the label attribute is Language-
Sensitive as defined by Section 2 of [RFC4287].
The f:feature element MAY contain child elements and attributes other
than those defined in this specification. Such "foreign markup" are
considered to be metadata applicable to the feature identified by the
f:feature element. Software agents MUST NOT stop processing or
signal an error or change their behavior as a result of encountering
such foreign markup.
An app:collection element MAY contain zero or more f:feature elements
but MUST NOT contain more than one with the same ref attribute value.
The order in which f:feature elements appear within the app:
collection element is insignificant.
The f:feature element MAY contain attributes included as part of the
atomCommonAttributes production defined by Section 2 of [RFC4287] or
any update thereof. When used on an f:feature element, such
attributes serve the same purpose described in [RFC4287] or their
corresponding specifications.
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3.1. Example
The following is an example of a collection supporting one
hypothetical required feature, one unsupported feature, and a number
of supported features.
<service
xmlns="http://www.w3.org/2007/app"
xmlns:atom="http://www.w3.org/2005/Atom"
xmlns:f="http://purl.org/atompub/features/1.0">
<workspace>
<atom:title>My Workspace</atom:title>
<collection href="...">
<atom:title>My Atom Collection</atom:title>
<accept>application/atom+xml;type=entry</accept>
<f:feature
ref="http://www.w3.org/2007/app/drafts" />
<f:feature
ref="http://www.w3.org/2007/app/xhtml-content" />
<f:feature
ref="http://www.w3.org/2007/app/preserve-extensions" />
<f:feature
ref="http://purl.org/syndication/thread/1.0" />
<f:feature
ref="http://www.w3.org/2007/app/binary-content"
status="unsupported" />
<f:feature
ref="http://code.google.com/apis/gdata/GoogleLogin"
href="http://code.google.com/apis/gdata/"
label="Google Login" status="required" />
</collection>
</workspace>
</app:server>
3.2. Contradictory Features
Some combinations of features can be contradictory when the support
level of one or more of those features is "required" and the others
are "supported". For instance, a collection that specifies that
XHTML values in the atom:title is required and that HTML in an atom:
title is supported is contradictory. Such contradictions can cause
problems for clients that are attempting to select an appropriate
collection based on the support level of various features. A service
document MUST NOT specify contradictory features. If a client
determines that the features specified in a service document are
contradictory, the client SHOULD proceed as if the support level for
each of those features is "supported".
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4. The f:type element
The content of an f:type element is a media-range as defined in
[RFC2616]. The media range specifies a type of content that can be
included in an atom:content element or referenced by the atom:content
src attribute.
type =
element f:type {
atomCommonAttributes,
( text? )
}
Media type parameters are allowed within f:type, but f:type has no
notion of preference - "accept-params" or "q" arguments, as specified
in Section 14.1 of [RFC2616] are not significant.
White space (as defined in [W3C.REC-xml-20040204]) around the f:type
element's media-range is insignificant and MUST be ignored.
Any number of f:type elements MAY appear as children of an f:feature
element. When used with features whose ref attributes identify the
"XML Content", "Binary Content" or "Reference Content" features as
defined in Section 6.1.1, the f:type elements specify the set of
media types that can be specified in the atom:content elements type
attribute. If no f:type element are present, clients SHOULD treat
this as equivalent to an f:type element with the content "*/*".
The order of f:type elements within a f:feature element is
insignificant.
4.1. An example f:feature using the f:type element
<f:feature
ref="http://www.w3.org/2007/app/binary-content">
<f:type>image/jpg</f:type>
<f:type>image/png</f:type>
<f:type>image/gif</f:type>
<f:type>text/*</f:type>
</f:feature>
5. Security Considerations
Specific features supported by a collection may introduce security
considerations and concerns beyond those discussed by the Atom
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Publishing Protocol and Atom Syndication Format specifications.
Implementors must refer to the specifications and description of each
feature to determine the security considerations relevant to each.
6. IANA Considerations
6.1. Registry of Atom Publishing Features
The Registry of Atom Publishing Features is maintained by IANA and
contains information about known features that can be supported by
Atom Publishing Protocol implementations. New assignments are
subject to IESG approval, as outlined in [RFC2434]. Requests should
be made by email to IANA, which will then forward the request to the
IESG, requesting approval. The request should use the following
template:
o Ref: (A globally unique IRI identifying the feature)
o Label: (A human-readable label for the feature)
o Description: (A human-readable description of the feature)
o Support Levels: (A description of the relevant support levels for
the feature)
o Contradictory Features: (A listing of features that are
contradictory to this feature when one or more are marked as
"required")
o Href: (A URI referencing a document containing a detailed
definition of the feature)
o Security Considerations:
6.1.1. Initial Assignments
The Registry of Features initially contains the following
assignments:
6.1.1.1. Drafts
o Ref: http://www.w3.org/2007/app/drafts
o Label: Drafts
o Support Levels:
* "supported" indicates that the collection accepts entries that
contain the app:draft control element.
* "required" indicates that the collection requires all entries
to contain the app:draft control element.
* "unsupported" indicates that the collection does not accept
entries that use the app:draft control element or that the
server will ignore the element if present.
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o Contradictory Features: none
o Description: The "Drafts" feature indicates that a collection
supports the use of the app:draft control element as defined in
section 13.1.1 of [I-D.ietf-atompub-protocol].
6.1.1.2. XHTML Content
o Ref: http://www.w3.org/2007/app/xhtml-content
o Label: XHTML Content
o Support Levels:
* "supported" indicates that the collection accepts entries that
provide XHTML in the atom:content element.
* "required" indicates that the collection requires all entries
to provide XHTML in the atom:content element.
* "unsupported" indicates that the collection does not accept
entries that provide XHTML in the atom:content element.
o Contradictory Features: http://www.w3.org/2007/app/html-content,
http://www.w3.org/2007/app/text-content,
http://www.w3.org/2007/app/xml-content,
http://www.w3.org/2007/app/binary-content,
http://www.w3.org/2007/app/ref-content
o Description: The "XHTML Content" feature indicates that a server
will accept the use of an XHTML value within the atom:content
element.
6.1.1.3. HTML Content
o Ref: http://www.w3.org/2007/app/html-content
o Label: HTML Content
o Support Levels:
* "supported" indicates that the collection accepts entries that
provide HTML in the atom:content element.
* "required" indicates that the collection requires all entries
to provide HTML in the atom:content element.
* "unsupported" indicates that the collection does not accept
entries that provide HTML in the atom:content element.
o Contradictory Features: http://www.w3.org/2007/app/xhtml-content,
http://www.w3.org/2007/app/text-content,
http://www.w3.org/2007/app/xml-content,
http://www.w3.org/2007/app/binary-content,
http://www.w3.org/2007/app/ref-content
o Description: The "HTML Content" feature indicates that a server
will accept the use of an escaped HTML value within the atom:
content element.
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6.1.1.4. Text Content
o Ref: http://www.w3.org/2007/app/text-content
o Label: Text Content
o Support Levels:
* "supported" indicates that the collection accepts entries that
provide plain text in the atom:content element.
* "required" indicates that the collection requires all entries
to provide plain text in the atom:content element.
* "unsupported" indicates that the collection does not accept
entries that provide plain text in the atom:content element.
o Contradictory Features: http://www.w3.org/2007/app/xhtml-content,
http://www.w3.org/2007/app/html-content,
http://www.w3.org/2007/app/xml-content,
http://www.w3.org/2007/app/binary-content,
http://www.w3.org/2007/app/ref-content
o Description: The "Text Content" feature indicates that a server
will accept the use of a plain text value within the atom:content
element.
6.1.1.5. XML Content
o Ref: http://www.w3.org/2007/app/xml-content
o Label: XML Content
o Support Levels:
* "supported" indicates that the collection accepts entries that
provide well-formed XML in the atom:content element.
* "required" indicates that the collection requires all entries
to provide well-formed XML in the atom:content element.
* "unsupported" indicates that the collection does not accept
entries that provide XML in the atom:content element. The MIME
media type of acceptable XML formats is specified using one or
more f:type elements within the f:feature.
o Contradictory Features: http://www.w3.org/2007/app/xhtml-content,
http://www.w3.org/2007/app/html-content,
http://www.w3.org/2007/app/text-content,
http://www.w3.org/2007/app/binary-content,
http://www.w3.org/2007/app/ref-content
o Description: The "XML Content" feature indicates that a server
will accept the use of well-formed XML content within the atom:
content element.
6.1.1.6. Binary Content
o Ref: http://www.w3.org/2007/app/binary-content
o Label: Binary Content
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o Support Levels:
* "supported" indicates that the collection accepts entries that
provide binary content in the atom:content element.
* "required" indicates that the collection requires all entries
to provide binary content in the atom:content element.
* "unsupported" indicates that the collection does not accept
entries that provide binary content in the atom:content
element. The MIME media type of acceptable binary formats is
specified using one or more f:type elements within the
f:feature.
o Contradictory Features: http://www.w3.org/2007/app/xhtml-content,
http://www.w3.org/2007/app/html-content,
http://www.w3.org/2007/app/text-content,
http://www.w3.org/2007/app/xml-content,
http://www.w3.org/2007/app/ref-content
o Description: The "Binary Content" feature indicates that a server
will accept Base-64 encoded binary data within the atom:content
element.
6.1.1.7. Referenced Content
o Ref: http://www.w3.org/2007/app/ref-content
o Label: XHTML Content
o Support Levels:
* "supported" indicates that the collection accepts entries that
use the atom:content src attribute to reference external
content.
* "required" indicates that the collection requires all entries
to use the atom:content src attribute to reference external
content.
* "unsupported" indicates that the collection does not accept
entries that use the atom:content src attribute. The MIME
media type of acceptable referenced resources is specified
using one or more f:type elements within the f:feature.
o Contradictory Features: http://www.w3.org/2007/app/xhtml-content,
http://www.w3.org/2007/app/html-content,
http://www.w3.org/2007/app/text-content,
http://www.w3.org/2007/app/xml-content,
http://www.w3.org/2007/app/binary-content
o Description: The "Referenced Content" feature indicates that a
server will accept atom:content elements that use the src
attribute to reference external content resources.
6.1.1.8. XHTML Title
o Ref: http://www.w3.org/2007/app/xhtml-title
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o Label: XHTML Title
o Support Levels:
* "supported" indicates that the collection accepts entries that
provide XHTML in the atom:title element.
* "required" indicates that the collectionrequires all entries to
provide XHTML in the atom:title element.
* "unsupported" indicates that the collection does not accept
entries that provide XHTML in the atom:title element.
o Contradictory Features: http://www.w3.org/2007/app/html-title,
http://www.w3.org/2007/app/text-title
o Description: The "XHTML Title" feature indicates that a server
will accept the use of an XHTML value within the atom:title
element.
6.1.1.9. HTML Title
o Ref: http://www.w3.org/2007/app/html-title
o Label: HTML Title
o Support Levels:
* "supported" indicates that the collection accepts entries that
provide HTML in the atom:title element.
* "required" indicates that the collection requires all entries
to provide HTML in the atom:title element.
* "unsupported" indicates that the collection does not accept
entries that provide HTML in the atom:title element.
o Contradictory Features: http://www.w3.org/2007/app/xhtml-title,
http://www.w3.org/2007/app/text-title
o Description: The "HTML Content" feature indicates that a server
will accept the use of an escaped HTML value within the atom:title
element.
6.1.1.10. Text Title
o Ref: http://www.w3.org/2007/app/text-title
o Label: Text Title
o Support Levels:
* "supported" indicates that the collection accepts entries that
provide plain text in the atom:title element.
* "required" indicates that the collection requires all entries
to provide plain text in the atom:title element.
* "unsupported" indicates that the collection does not accept
entries that provide plain text in the atom:title element.
o Contradictory Features: http://www.w3.org/2007/app/xhtml-title,
http://www.w3.org/2007/app/html-title
o Description: The "Text Content" feature indicates that a server
will accept the use of a plain text value within the atom:title
element.
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6.1.1.11. XHTML Summary
o Ref: http://www.w3.org/2007/app/xhtml-summary
o Label: XHTML Summary
o Support Levels:
* "supported" indicates that the collection accepts entries that
provide XHTML in the atom:summary element.
* "required" indicates that the collection requires all entries
to provide XHTML in the atom:summary element.
* "unsupported" indicates that the collection does not accept
entries that provide XHTML in the atom:summary element.
o Contradictory Features: http://www.w3.org/2007/app/html-summary,
http://www.w3.org/2007/app/text-summary
o Description: The "XHTML Summary" feature indicates that a server
will accept the use of an XHTML value within the atom:summary
element.
6.1.1.12. HTML Summary
o Ref: http://www.w3.org/2007/app/html-summary
o Label: HTML Summary
o Support Levels:
* "supported" indicates that the collection accepts entries that
provide HTML in the atom:summary element.
* "required" indicates that the collection requires all entries
to provide HTML in the atom:summary element.
* "unsupported" indicates that the collection does not accept
entries that provide HTML in the atom:summary element.
o Contradictory Features: http://www.w3.org/2007/app/xhtml-summary,
http://www.w3.org/2007/app/text-summary
o Description: The "HTML Summary" feature indicates that a server
will accept the use of an escaped HTML value within the atom:
summary element.
6.1.1.13. Text Summary
o Ref: http://www.w3.org/2007/app/text-summary
o Label: Text Summary
o Support Levels:
* "supported" indicates that the collection accepts entries that
provide plain text in the atom:summary element.
* "required" indicates that the collection requires all entries
to provide plain text in the atom:summary element.
* "unsupported" indicates that the collection does not accept
entries that provide plain text in the atom:summary element.
o Contradictory Features: http://www.w3.org/2007/app/xhtml-summary,
http://www.w3.org/2007/app/html-summary
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o Description: The "Text Summary" feature indicates that a server
will accept the use of a plain text value within the atom:summary
element.
6.1.1.14. Auto Summary
o Ref: http://www.w3.org/2007/app/auto-summary
o Label: Auto Summary
o Support Levels:
* "supported" indicates that the server will automatically
generate an atom:summary element if the entry provided by the
client does not already contain one.
* "required" indicates that the server will automatically
generate an atom:summary element regardless of whether the
entry already contains one.
* "unsupported" indicates that the server will not automatically
generate an atom:summary element.
o Contradictory Features: http://www.w3.org/2007/app/xhtml-summary,
http://www.w3.org/2007/app/html-summary,
http://www.w3.org/2007/app/text-summary
o Description: The "Auto Summary" feature indicates that a server
will autogenerate the value of the atom:summary element and will
either reject or ignore attempts by the client to modify the value
of atom:summary.
6.1.1.15. XHTML Rights
o Ref: http://www.w3.org/2007/app/xhtml-rights
o Label: XHTML Rights
o Support Levels:
* "supported" indicates that the collection accepts entries that
provide XHTML in the atom:rights element.
* "required" indicates that the collection requires all entries
to provide XHTML in the atom:rights element.
* "unsupported" indicates that the collection does not accept
entries that provide XHTML in the atom:rights element.
o Contradictory Features: http://www.w3.org/2007/app/html-rights,
http://www.w3.org/2007/app/text-rights
o Description: The "XHTML Rights" feature indicates that a server
will accept the use of an XHTML value within the atom:rights
element.
6.1.1.16. HTML Rights
o Ref: http://www.w3.org/2007/app/html-rights
o Label: HTML Rights
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o Support Levels:
* "supported" indicates that the collection accepts entries that
provide HTML in the atom:rights element.
* "required" indicates that the collection requires all entries
to provide HTML in the atom:rights element.
* "unsupported" indicates that the collection does not accept
entries that provide HTML in the atom:rights element.
o Contradictory Features: http://www.w3.org/2007/app/xhtml-rights,
http://www.w3.org/2007/app/text-rights
o Description: The "HTML Rights" feature indicates that a server
will accept the use of an escaped HTML value within the atom:
rights element.
6.1.1.17. Text Rights
o Ref: http://www.w3.org/2007/app/text-rights
o Label: Text Rights
o Support Levels:
* "supported" indicates that the collection accepts entries that
provide plain text in the atom:rights element.
* "required" indicates that the collection requires all entries
to provide plain text in the atom:rights element.
* "unsupported" indicates that the collection does not accept
entries that provide plain text in the atom:rights element.
o Contradictory Features: http://www.w3.org/2007/app/xhtml-rights,
http://www.w3.org/2007/app/html-rights
o Description: The "Text Rights" feature indicates that a server
will accept the use of a plain text value within the atom:rights
element.
6.1.1.18. Authenticated Author
o Ref: http://www.w3.org/2007/app/auth-author
o Label: Authenticated Author
o Support Levels:
* "supported" indicates that the server will automatically
generate the atom:author element based on the client's
authenticated identity.
* For this feature,"required" is synonymous with "supported".
* "unsupported" indicates that the server will not automatically
generate the atom:author for an entry based on the client's
authenticated identity.
o Contradictory Features:
http://www.w3.org/2007/app/multiple-authors
o Description: The "Authenticated Author" feature indicates that a
server will use the authenticated identity of the client to
determine the values to use within the atom:author element.
Attempts by a client to manually set or modify the author
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information will either be rejected or ignored by the server.
6.1.1.19. Slug
o Ref: http://www.w3.org/2007/app/slug
o Label: Slug
o Support Levels:
* "supported" indicates that the collection accepts the use of
the Slug header in POST requests.
* "required" indicates that the collection requires that the Slug
header be used for all POST requests.
* "unsupported" indicates that the collection will not accept the
use of the Slug header in POST requests or that the header will
be ignored.
o Contradictory Features: none
o Description: The "Slug" feature indicates that a server will use
the Slug request header defined in section 9.7 of
[I-D.ietf-atompub-protocol] to set the URI of newly created
resources.
6.1.1.20. Multiple Categories
o Ref: http://www.w3.org/2007/app/multiple-categories
o Label: Multiple Categories
o Support Levels:
* "supported" indicates that the collection accepts the use of
multiple atom:category elements within an entry.
* For this feature, "required" is synonymous with "supported".
* "unsupported" indicates that the collection will not accept
entries with multiple atom:category elements or that that
additional atom:category elements will be ignored.
o Contradictory Features: none
o Description: The "Multiple Categories" feature indicates that a
server will accept entries that contain multiple atom:category
elements.
6.1.1.21. Multiple Authors
o Ref: http://www.w3.org/2007/app/multiple-authors
o Label: Multiple Authors
o Support Levels:
* "supported" indicates that the collection accepts the use of
multiple atom:author elements within an entry.
* For this feature, "required" is synonymous with "supported".
* "unsupported" indicates that the collection will not accept
entries with multiple atom:author elements or that the
additional atom:author elements will be ignored.
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o Contradictory Features: http://www.w3.org/2007/app/auth-author
o Description: The "Multiple Authors" feature indicates that a
server will accept and preserve multiple atom:author elements
contained by an entry.
6.1.1.22. Multiple Contributors
o Ref: http://www.w3.org/2007/app/contributors
o Label: Multiple Contributors
o Support Levels:
* "supported" indicates that the collection accepts the use of
multiple atom:contributor elements within an entry.
* For this feature, "required" is synonymous with "supported".
* "unsupported" indicates that the collection will not accept
entries with multiple atom:contributor elements or that the
additional atom:contributor elements will be ignored.
o Contradictory Features: none
o Description: The "Multiple Contributors" feature indicates that a
server will accept and preserve atom:contributor elements
contained by an entry.
6.1.1.23. Preserve Infoset
o Ref: http://www.w3.org/2007/app/preserve-infoset
o Label: Preserve Infoset
o Support Levels:
* "supported" indicates that the collection will store entries in
such a way as to preserve the complete XML infoset of the entry
document.
* For this feature, "required" is synonymous with "supported".
* "unsupported" indicates that the collection will not preserve
the complete XML infoset of the entry when storing.
o Contradictory Features: none
o Description: The "Preserve Infoset" feature indicates that a
server will preserve the complete XML Infoset
[W3C.REC-xml-infoset-20040204] of entries POST or PUT to a
collection.
6.1.1.24. Preserve IDs
o Ref: http://www.w3.org/2007/app/preserve-id
o Label: Preserve IDs
o Support Levels:
* "supported" indicates that the collection will preserve the
value of the atom:id element as provided by the client.
* For this feature, "required" is synonymous with "supported".
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* "unsupported" indicates that the collection will not preserve
the value of the atom:id element as provided by the client
(e.g. the server will generate it's own value for the atom:id
element.
o Contradictory Features: none
o Description: The "Preserve IDs" feature indicates that a server
will preserve the value of atom:id elements as provided by a
client.
6.1.1.25. Preserve Dates
o Ref: http://www.w3.org/2007/app/preserve-updated
o Label: Preserve Dates
o Support Levels:
* "supported" indicates that the collection will preserve the
value of all date elements as provided by the client.
* For this feature,"required" is synonymous with "supported".
* "unsupported" indicates that the collection will not preserve
the value of date elements as provided by the client (e.g. the
server will generate it's own value for the date elements.
o Contradictory Features: none
o Description: The "Preserve Dates" feature indicates that a server
will preserve the value of the atom:updated and atom:published
elements as provided by a client.
6.1.1.26. Preserve Extensions
o Ref: http://www.w3.org/2007/app/preserve-extensions
o Label: Preserve Extensions
o Support Levels:
* "supported" indicates that the collection will preserve all
extensions contained within an entry.
* For this feature, "required" is synonymous with "supported".
* "unsupported" indicates that the collection will not preserve
all extensions contained within an entry, however some
extensions may be preserved.
o Contradictory Features: none
o Description: The "Preserve Extensions" feature indicates that a
server will preserve unknown foreign markup contained within an
entry.
6.1.1.27. Preserve Links
o Ref: http://www.w3.org/2007/app/preserve-links
o Label: Preserve Links
o Support Levels:
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* "supported" indicates that the collection will preserve all
atom:link elements contained within an entry.
* For this feature, "required" is synonymous with "supported".
* "unsupported" indicates that the collection will not preserve
all atom:links contained within an entry, however some atom:
link elements may be preserved.
o Contradictory Features: none
o Description: The "Preserve Links" feature indicates that a server
will preserve all atom:link elements contained within an entry.
6.1.1.28. Preserve Rights
o Ref: http://www.w3.org/2007/app/preserve-rights
o Label: Preserve Rights
o Support Levels:
* "supported" indicates that the collection will preserve the
value of the atom:rights element as well as all License Links
[RFC4946] contained within an entry.
* For this feature, "required" is synonymous with "supported".
* "unsupported" indicates that the collection may not preserve
the value of the atom:rights element or all License Links
[RFC4946], however, some rights information may be preserved.
o Contradictory Features: none
o Description: The "Preserve Rights" feature indicates that a server
will preserve all atom:rights elements and License Links [RFC4946]
contained within an entry.
6.1.1.29. Threading
o Ref: http://purl.org/syndication/thread/1.0
o Label: Threading
o Support Levels:
* "supported" indicates that the collection accepts entries that
contain the in-reply-to element as defined by [RFC4685].
* "required" indicates that the collection requires that all
entries contain an in-reply-to element.
* "unsupported" indicates that the collection will not accept
entries containing the in-reply-to element or that the element
will be ignored if present.
o Contradictory Features: none
o Description: The Feed Thread feature indicates that the collection
accepts entries that contain the in-reply-to element as defined by
[RFC4685].
6.1.1.30. Scheduled Publishing
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o Ref: http://www.w3.org/2007/app/scheduled-publishing
o Label: Scheduled Publishing
o Support Levels:
* "supported" indicates that the collection allows clients to
specify a future instant in time for the atom:published element
when the entry should be made publicly available.
* "required" indicates that the collection requires clients to
specify a future instant in time for the atom:published
element.
* "unsupported" indicates that the collection will not allow
clients to specify a future instance in time for the atom:
published element.
o Contradictory Features: none
o Description: The "Scheduled Publishing" feature indicates that a
collection allows clients to set the value of an entries atom:
published element to some future point in time after which the
entry will be made publicly visible. Prior to that time, the
entry will be considered to be in a draft state and SHOULD contain
an app:draft control element with a value of "yes".
7. Normative References
[I-D.ietf-atompub-protocol]
Hora, B. and J. Gregorio, "The Atom Publishing Protocol",
draft-ietf-atompub-protocol-17 (work in progress),
July 2007.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2434] Narten, T. and H. Alvestrand, "Guidelines for Writing an
IANA Considerations Section in RFCs", BCP 26, RFC 2434,
October 1998.
[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.
[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., Ed. and R. Sayre, Ed., "The Atom
Syndication Format", RFC 4287, December 2005.
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[RFC4685] Snell, J., "Atom Threading Extensions", RFC 4685,
September 2006.
[RFC4946] Snell, J., "Atom License Extension", RFC 4946, July 2007.
[W3C.REC-xml-20040204]
Maler, E., Sperberg-McQueen, C., Paoli, J., Yergeau, F.,
and T. Bray, "Extensible Markup Language (XML) 1.0 (Third
Edition)", World Wide Web Consortium FirstEdition REC-xml-
20040204, February 2004,
<http://www.w3.org/TR/2004/REC-xml-20040204>.
[W3C.REC-xml-infoset-20040204]
Tobin, R. and J. Cowan, "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>.
[W3C.REC-xml-names-19990114]
Hollander, D., Bray, T., and A. Layman, "Namespaces in
XML", World Wide Web Consortium FirstEdition REC-xml-
names-19990114, January 1999,
<http://www.w3.org/TR/1999/REC-xml-names-19990114>.
[W3C.REC-xmlbase-20010627]
Marsh, J., "XML Base", World Wide Web Consortium
Recommendation REC-xmlbase-20010627, June 2001,
<http://www.w3.org/TR/2001/REC-xmlbase-20010627>.
Appendix A. Acknowledgements
The author acknowledges the feedback from the other members of the
IETF Atom Publishing working group during the development of this
specification.
Author's Address
James M Snell
Phone:
Email: jasnell@gmail.com
URI: http://snellspace.com
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Full Copyright Statement
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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.
This document and the information contained herein are provided on an
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Copies of IPR disclosures made to the IETF Secretariat and any
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Snell Expires February 22, 2008 [Page 22]
