draft-ietf-atompub-format-04.txt   draft-ietf-atompub-format-05.txt 
Network Working Group M. Nottingham, Ed. Network Working Group M. Nottingham, Ed.
Internet-Draft Internet-Draft
Expires: July 11, 2005 R. Sayre, Ed. Expires: July 27, 2005 R. Sayre, Ed.
Boswijck Memex Consulting Boswijck Memex Consulting
January 10, 2005 January 26, 2005
The Atom Syndication Format The Atom Syndication Format
draft-ietf-atompub-format-04 draft-ietf-atompub-format-05
Status of this Memo Status of this Memo
By submitting this Internet-Draft, I certify that any applicable By submitting this Internet-Draft, I certify that any applicable
patent or other IPR claims of which I am aware have been disclosed, patent or other IPR claims of which I am aware have been disclosed,
and any of which I become aware will be disclosed, in accordance with and any of which I become aware will be disclosed, in accordance with
RFC 3668. RFC 3668.
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF), its areas, and its working groups. Note that Task Force (IETF), its areas, and its working groups. Note that
skipping to change at page 1, line 35 skipping to change at page 1, line 35
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
The list of current Internet-Drafts can be accessed at The list of current Internet-Drafts can be accessed at
http://www.ietf.org/ietf/1id-abstracts.txt. http://www.ietf.org/ietf/1id-abstracts.txt.
The list of Internet-Draft Shadow Directories can be accessed at The list of Internet-Draft Shadow Directories can be accessed at
http://www.ietf.org/shadow.html. http://www.ietf.org/shadow.html.
This Internet-Draft will expire on July 11, 2005. This Internet-Draft will expire on July 27, 2005.
Copyright Notice Copyright Notice
Copyright (C) The Internet Society (2005). All Rights Reserved. Copyright (C) The Internet Society (2005). All Rights Reserved.
Abstract Abstract
This document specifies Atom, an XML-based Web content and metadata This document specifies Atom, an XML-based Web content and metadata
syndication format. syndication format.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 4 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 4
1.1 Editorial Notes . . . . . . . . . . . . . . . . . . . . . 4 1.1 Editorial Notes . . . . . . . . . . . . . . . . . . . . . 4
1.2 Example . . . . . . . . . . . . . . . . . . . . . . . . . 5 1.2 Example . . . . . . . . . . . . . . . . . . . . . . . . . 5
1.3 Conformance . . . . . . . . . . . . . . . . . . . . . . . 5 1.3 Conformance . . . . . . . . . . . . . . . . . . . . . . . 5
1.4 Notational Conventions . . . . . . . . . . . . . . . . . . 5 1.4 Notational Conventions . . . . . . . . . . . . . . . . . . 5
2. Atom Documents . . . . . . . . . . . . . . . . . . . . . . . 7 2. Atom Documents . . . . . . . . . . . . . . . . . . . . . . . 7
3. Common Atom Constructs . . . . . . . . . . . . . . . . . . . 8 3. Common Atom Constructs . . . . . . . . . . . . . . . . . . . 9
3.1 Text Constructs . . . . . . . . . . . . . . . . . . . . . 8 3.1 Text Constructs . . . . . . . . . . . . . . . . . . . . . 9
3.1.1 "type" Attribute . . . . . . . . . . . . . . . . . . . 8 3.1.1 "type" Attribute . . . . . . . . . . . . . . . . . . . 9
3.2 Person Constructs . . . . . . . . . . . . . . . . . . . . 9 3.2 Person Constructs . . . . . . . . . . . . . . . . . . . . 10
3.2.1 "atom:name" Element . . . . . . . . . . . . . . . . . 9 3.2.1 The "atom:name" Element . . . . . . . . . . . . . . . 10
3.2.2 "atom:uri" Element . . . . . . . . . . . . . . . . . . 9 3.2.2 The "atom:uri" Element . . . . . . . . . . . . . . . . 10
3.2.3 "atom:email" Element . . . . . . . . . . . . . . . . . 9 3.2.3 The "atom:email" Element . . . . . . . . . . . . . . . 11
3.3 Date Constructs . . . . . . . . . . . . . . . . . . . . . 9 3.3 Date Constructs . . . . . . . . . . . . . . . . . . . . . 11
3.4 Service Constructs . . . . . . . . . . . . . . . . . . . . 9 3.4 Service Constructs . . . . . . . . . . . . . . . . . . . . 11
3.4.1 "href" Attribute . . . . . . . . . . . . . . . . . . . 10 3.4.1 The "href" Attribute . . . . . . . . . . . . . . . . . 11
3.5 Link Constructs . . . . . . . . . . . . . . . . . . . . . 10 3.5 Identity Constructs . . . . . . . . . . . . . . . . . . . 11
3.5.1 "rel" Attribute . . . . . . . . . . . . . . . . . . . 10 3.5.1 Dereferencing Identity Constructs . . . . . . . . . . 12
3.5.2 "type" Attribute . . . . . . . . . . . . . . . . . . . 11 3.5.2 Comparing Identity Constructs . . . . . . . . . . . . 12
3.5.3 "href" Attribute . . . . . . . . . . . . . . . . . . . 11 4. Element Definitions . . . . . . . . . . . . . . . . . . . . 14
3.5.4 "hreflang" Attribute . . . . . . . . . . . . . . . . . 11 4.1 The "atom:feed" Element . . . . . . . . . . . . . . . . . 14
3.5.5 "title" Attribute . . . . . . . . . . . . . . . . . . 11 4.1.1 The "version" Attribute . . . . . . . . . . . . . . . 14
3.5.6 "length" Attribute . . . . . . . . . . . . . . . . . . 11
3.6 Identity Constructs . . . . . . . . . . . . . . . . . . . 12
3.6.1 Dereferencing Identity Constructs . . . . . . . . . . 12
3.6.2 Comparing Identity Constructs . . . . . . . . . . . . 12
3.7 The Category Construct . . . . . . . . . . . . . . . . . . 13
3.7.1 The "term" Attribute . . . . . . . . . . . . . . . . . 13
3.7.2 The "scheme" Attribute . . . . . . . . . . . . . . . . 13
3.7.3 The "label" attribute . . . . . . . . . . . . . . . . 13
4. The "atom:feed" Element . . . . . . . . . . . . . . . . . . 14
4.1 "version" Attribute . . . . . . . . . . . . . . . . . . . 14
4.2 The "atom:head" Element . . . . . . . . . . . . . . . . . 14 4.2 The "atom:head" Element . . . . . . . . . . . . . . . . . 14
4.2.1 "atom:title" Element . . . . . . . . . . . . . . . . . 14 4.2.1 Usage of "atom:head" within "atom:entry" . . . . . . . 16
4.2.2 "atom:link" Element . . . . . . . . . . . . . . . . . 14 4.3 The "atom:entry" Element . . . . . . . . . . . . . . . . . 16
4.2.3 "atom:category" Element . . . . . . . . . . . . . . . 15 4.4 The "atom:title" Element . . . . . . . . . . . . . . . . . 18
4.2.4 "atom:introspection" Element . . . . . . . . . . . . . 15 4.5 The "atom:id" Element . . . . . . . . . . . . . . . . . . 18
4.2.5 "atom:post" Element . . . . . . . . . . . . . . . . . 15 4.6 The "atom:link" Element . . . . . . . . . . . . . . . . . 18
4.2.6 "atom:author" Element . . . . . . . . . . . . . . . . 15 4.6.1 The "href" Attribute . . . . . . . . . . . . . . . . . 19
4.2.7 "atom:contributor" Element . . . . . . . . . . . . . . 15 4.6.2 The "rel" Attribute . . . . . . . . . . . . . . . . . 19
4.2.8 "atom:tagline" Element . . . . . . . . . . . . . . . . 15 4.6.3 The "type" Attribute . . . . . . . . . . . . . . . . . 20
4.2.9 "atom:id" Element . . . . . . . . . . . . . . . . . . 16 4.6.4 The "hreflang" Attribute . . . . . . . . . . . . . . . 20
4.2.10 "atom:generator" Element . . . . . . . . . . . . . . 16 4.6.5 The "title" Attribute . . . . . . . . . . . . . . . . 20
4.2.11 "atom:copyright" Element . . . . . . . . . . . . . . 16 4.6.6 The "length" Attribute . . . . . . . . . . . . . . . . 20
4.2.12 "atom:info" Element . . . . . . . . . . . . . . . . 16 4.7 The "atom:updated" Element . . . . . . . . . . . . . . . . 20
4.2.13 "atom:updated" Element . . . . . . . . . . . . . . . 16 4.8 The "atom:published" Element . . . . . . . . . . . . . . . 21
5. The "atom:entry" Element . . . . . . . . . . . . . . . . . . 18 4.9 The "atom:author" Element . . . . . . . . . . . . . . . . 21
5.1 "atom:title" Element . . . . . . . . . . . . . . . . . . . 18 4.10 The "atom:contributor" Element . . . . . . . . . . . . . 21
5.2 "atom:link" Element . . . . . . . . . . . . . . . . . . . 18 4.11 The "atom:host" Element . . . . . . . . . . . . . . . . 21
5.3 "atom:category" Element . . . . . . . . . . . . . . . . . 18 4.12 The "atom:copyright" Element . . . . . . . . . . . . . . 21
5.4 "atom:edit" Element . . . . . . . . . . . . . . . . . . . 19 4.13 The "atom:category" Element . . . . . . . . . . . . . . 22
5.5 "atom:author" Element . . . . . . . . . . . . . . . . . . 19 4.13.1 The "term" Attribute . . . . . . . . . . . . . . . . 22
5.6 "atom:contributor" Element . . . . . . . . . . . . . . . . 19 4.13.2 The "scheme" Attribute . . . . . . . . . . . . . . . 22
5.7 "atom:host" Element . . . . . . . . . . . . . . . . . . . 19 4.13.3 The "label" attribute . . . . . . . . . . . . . . . 22
5.8 "atom:id" Element . . . . . . . . . . . . . . . . . . . . 19 4.14 The "atom:summary" Element . . . . . . . . . . . . . . . 22
5.9 "atom:updated" Element . . . . . . . . . . . . . . . . . . 19 4.15 The "atom:content" Element . . . . . . . . . . . . . . . 23
5.10 "atom:published" Element . . . . . . . . . . . . . . . . 20 4.15.1 The "type" attribute . . . . . . . . . . . . . . . . 23
5.11 "atom:summary" Element . . . . . . . . . . . . . . . . . 20 4.15.2 The "src" attribute . . . . . . . . . . . . . . . . 23
5.12 "atom:content" Element . . . . . . . . . . . . . . . . . 20 4.15.3 Processing Model . . . . . . . . . . . . . . . . . . 24
5.12.1 "type" attribute . . . . . . . . . . . . . . . . . . 20 4.16 The "atom:introspection" Element . . . . . . . . . . . . 25
5.12.2 "src" attribute . . . . . . . . . . . . . . . . . . 21 4.17 The "atom:post" Element . . . . . . . . . . . . . . . . 25
5.12.3 Processing Model . . . . . . . . . . . . . . . . . . 21 4.18 The "atom:edit" Element . . . . . . . . . . . . . . . . 25
5.13 "atom:copyright" Element . . . . . . . . . . . . . . . . 22 4.19 The "atom:tagline" Element . . . . . . . . . . . . . . . 25
5.14 "atom:head" Element . . . . . . . . . . . . . . . . . . 22 4.20 The "atom:generator" Element . . . . . . . . . . . . . . 25
6. Managing Feed State . . . . . . . . . . . . . . . . . . . . 23 4.21 The "atom:info" Element . . . . . . . . . . . . . . . . 26
7. Securing Atom Documents . . . . . . . . . . . . . . . . . . 24 5. Managing Feed State . . . . . . . . . . . . . . . . . . . . 27
7.1 Digital Signatures . . . . . . . . . . . . . . . . . . . . 24 6. Securing Atom Documents . . . . . . . . . . . . . . . . . . 28
7.2 Encryption . . . . . . . . . . . . . . . . . . . . . . . . 24 6.1 Digital Signatures . . . . . . . . . . . . . . . . . . . . 28
8. Embedding Atom in Other Formats . . . . . . . . . . . . . . 25 6.2 Encryption . . . . . . . . . . . . . . . . . . . . . . . . 28
9. Extending Atom . . . . . . . . . . . . . . . . . . . . . . . 26 7. Embedding Atom in Other Formats . . . . . . . . . . . . . . 29
10. IANA Considerations . . . . . . . . . . . . . . . . . . . . 27 8. Extending Atom . . . . . . . . . . . . . . . . . . . . . . . 30
10.1 Registry of Link Relations . . . . . . . . . . . . . . . 27 9. IANA Considerations . . . . . . . . . . . . . . . . . . . . 31
11. Security Considerations . . . . . . . . . . . . . . . . . . 29 9.1 Registry of Link Relations . . . . . . . . . . . . . . . . 31
12. References . . . . . . . . . . . . . . . . . . . . . . . . . 30 10. Security Considerations . . . . . . . . . . . . . . . . . . 33
12.1 Normative References . . . . . . . . . . . . . . . . . . . 30 11. References . . . . . . . . . . . . . . . . . . . . . . . . . 34
12.2 Informative References . . . . . . . . . . . . . . . . . . 31 11.1 Normative References . . . . . . . . . . . . . . . . . . . 34
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . 32 11.2 Informative References . . . . . . . . . . . . . . . . . . 35
A. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 33 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . 36
B. Revision History . . . . . . . . . . . . . . . . . . . . . . 34 A. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 37
Intellectual Property and Copyright Statements . . . . . . . 36 B. Collected RELAX NG Compact Schema . . . . . . . . . . . . . 38
C. Revision History . . . . . . . . . . . . . . . . . . . . . . 45
Intellectual Property and Copyright Statements . . . . . . . 47
1. Introduction 1. Introduction
Atom is an XML-based document format intended to allow lists of Atom is an XML-based document format which describes lists of related
related information, known as "feeds". Feeds are composed of a information known as "feeds". Feeds are composed of a number of
number of items, known as "entries", each with an extensible set of items, known as "entries", each with an extensible set of attached
attached metadata. For example, each entry has a title. metadata. For example, each entry has a title.
The primary use case that Atom addresses is the syndication of Web The primary use case that Atom addresses is the syndication of Web
content such as Weblogs and news headlines to Web sites as well as content such as Weblogs and news headlines to Web sites as well as
directly to user agents. However, nothing precludes it from being directly to user agents. However, nothing precludes it from being
used for other purposes and kinds of content. used for other purposes and kinds of content.
Details of communication protocols between software agents using Atom Details of communication protocols between software agents using Atom
can be found in the Atom Protocol specification [Atom-protocol]. can be found in the Atom Protocol specification [Atom-protocol].
[[ more motivation / design principles ]] [[ more motivation / design principles ]]
skipping to change at page 5, line 10 skipping to change at page 5, line 10
This document is an early draft and known to be incomplete. Topics This document is an early draft and known to be incomplete. Topics
marked [[like this]] indicate where additional text is likely to be marked [[like this]] indicate where additional text is likely to be
added. added.
1.2 Example 1.2 Example
A minimal, single-entry Atom Feed Document: A minimal, single-entry Atom Feed Document:
<?xml version="1.0" encoding="UTF-8"?> <?xml version="1.0" encoding="UTF-8"?>
<feed version="draft-ietf-atompub-format-04 <feed version="draft-ietf-atompub-format-05:do not deploy"
: do not deploy" xmlns="http://purl.org/atom/ns#draft-ietf-atompub-format-05">
xmlns="http://purl.org/atom/ns#draft-ietf-atompub-format-04
">
<head> <head>
<title>Example Feed</title> <title>Example Feed</title>
<link href="http://example.org/"/> <link href="http://example.org/"/>
<updated>2003-12-13T18:30:02Z</updated> <updated>2003-12-13T18:30:02Z</updated>
<author> <author>
<name>John Doe</name> <name>John Doe</name>
</author> </author>
</head> </head>
<entry> <entry>
<title>Atom-Powered Robots Run Amok</title> <title>Atom-Powered Robots Run Amok</title>
skipping to change at page 5, line 45 skipping to change at page 5, line 43
1.4 Notational Conventions 1.4 Notational Conventions
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in BCP 14, [RFC2119]. document are to be interpreted as described in BCP 14, [RFC2119].
This specification uses XML Namespaces [W3C.REC-xml-names-19990114] This specification uses XML Namespaces [W3C.REC-xml-names-19990114]
to uniquely identify XML elements and attribute names. It uses the to uniquely identify XML elements and attribute names. It uses the
following namespace prefixes for the indicated namespace URIs; following namespace prefixes for the indicated namespace URIs;
"atom": http://purl.org/atom/ns#draft-ietf-atompub-format-04 "atom": http://purl.org/atom/ns#draft-ietf-atompub-format-05
Note that the choice of any namespace prefix is arbitrary and not Note that the choice of any namespace prefix is arbitrary and not
semantically significant. semantically significant.
Atom is specified using terms from the XML Infoset Atom is specified using terms from the XML Infoset
[W3C.REC-xml-infoset-20011024]. However, this specification uses a [W3C.REC-xml-infoset-20011024]. However, this specification uses a
shorthand for two common terms; the phrase "Information Item" is shorthand for two common terms; the phrase "Information Item" is
omitted when naming Element Information Items and Attribute omitted when naming Element Information Items and Attribute
Information Items. Information Items.
Therefore, when this specification uses the term "element," it is Therefore, when this specification uses the term "element," it is
referring to an Element Information Item in Infoset terms. Likewise, referring to an Element Information Item in Infoset terms. Likewise,
when it uses the term "attribute," it is referring to an Attribute when it uses the term "attribute," it is referring to an Attribute
Information Item. Information Item.
Some sections of this specification are illustrated with fragments of
a non-normative RELAX NG Compact schema [RELAX-NG]. However, the
text of this specification provides the definition of conformance. A
collected schema appears in an informative appendix.
2. Atom Documents 2. Atom Documents
This specification describes two kinds of Atom Documents; Atom Feed This specification describes two kinds of Atom Documents; Atom Feed
Documents and Atom Entry Documents. Documents and Atom Entry Documents.
An Atom Feed Document is a representation of an Atom feed, including An Atom Feed Document is a representation of an Atom feed, including
metadata about the feed, and some or all of the entries associated metadata about the feed, and some or all of the entries associated
with it. Its document element is atom:feed. with it. Its document element is atom:feed.
An Atom Entry Document represents exactly one Atom Entry, outside of An Atom Entry Document represents exactly one Atom Entry, outside of
the context of an Atom Feed. Its document element is atom:entry. the context of an Atom Feed. Its document element is atom:entry.
namespace atom =
"http://purl.org/atom/ns#draft-ietf-atompub-format-05"
start = atomFeed | atomEntry
Both kinds of Atom documents are specified in terms of the XML Both kinds of Atom documents are specified in terms of the XML
Information Set, serialised as XML 1.0 [W3C.REC-xml-20040204] and Information Set, serialised as XML 1.0 [W3C.REC-xml-20040204] and
identified with the "application/atom+xml" media type. Atom identified with the "application/atom+xml" media type. Atom
Documents MUST be well-formed XML. Documents MUST be well-formed XML.
[[ Validity? ]]
Atom constrains the appearance and content of elements and Atom constrains the appearance and content of elements and
attributes; unless otherwise stated, Atom Documents MAY contain other attributes; unless otherwise stated, Atom Documents MAY contain other
Information Items as appropriate. In particular, Comment Information Information Items as appropriate. In particular, Comment Information
Items and Processing Instruction Information Items SHOULD be ignored Items and Processing Instruction Information Items SHOULD be ignored
in the normal processing of an Atom Document. in the normal processing of an Atom Document.
Any element in an Atom Document MAY have an xml:base attribute. XML Any element in an Atom Document MAY have an xml:base attribute. XML
Base [W3C.REC-xmlbase-20010627] processing MUST be applied to any Base [W3C.REC-xmlbase-20010627] processing MUST be applied to any
relative reference [RFC2396bis] present in an Atom Document. This relative reference [RFC3986] present in an Atom Document. This
includes such elements and attributes as specified by Atom itself, as includes such elements and attributes as specified by Atom itself, as
well as those specified by extensions to Atom. well as those specified by extensions to Atom.
Any element in an Atom Document MAY have an xml:lang attribute, whose Any element in an Atom Document MAY have an xml:lang attribute, whose
content indicates the default natural language of the element's content indicates the natural language of the element's content.
content. Requirements regarding the content and interpretation of Requirements regarding the content and interpretation of xml:lang are
xml:lang are specified in XML 1.0 [W3C.REC-xml-20040204] Section specified in XML 1.0 [W3C.REC-xml-20040204] Section 2.12.
2.12.
atomCommonAttributes =
attribute xml:base { atomUri }?,
attribute xml:lang { atomLanguageTag }?
[[ discussion of URI escaping and i18n, IRI ]] [[ discussion of URI escaping and i18n, IRI ]]
[[ discussion of white space ]] [[ discussion of white space ]]
Atom is extensible. See the section titled 'Extending Atom' later in Atom is extensible. See the section titled 'Extending Atom' later in
this document for a full description of how Atom Documents can be this document for a full description of how Atom Documents can be
extended. extended.
3. Common Atom Constructs 3. Common Atom Constructs
Many of Atom's elements share a few common structures. This section Many of Atom's elements share a few common structures. This section
defines a few such structures and their requirements, for convenient defines a few such structures and their requirements for convenient
reference by the appropriate element definitions. reference by the appropriate element definitions.
When an element is identified as being a particular kind of When an element is identified as being a particular kind of
construct, it inherits the corresponding requirements from that construct, it inherits the corresponding requirements from that
construct's definition in this section. construct's definition in this section.
3.1 Text Constructs 3.1 Text Constructs
A Text construct contains human readable text, usually in fairly A Text construct contains human readable text, usually in fairly
small quantities. small quantities.
atomPlainTextConstruct =
atomCommonAttributes,
attribute type { "TEXT" | "HTML" }?,
text
atomXHTMLTextConstruct =
atomCommonAttributes,
attribute type { "XHTML" },
(text|anyElement)*
atomTextConstruct = atomPlainTextConstruct | atomXHTMLTextConstruct
3.1.1 "type" Attribute 3.1.1 "type" Attribute
Text constructs MAY have a "type" attribute. When present, the value Text constructs MAY have a "type" attribute. When present, the value
MUST be one of "TEXT", "HTML" or "XHTML". If the "type" attribute is MUST be one of "TEXT", "HTML" or "XHTML". If the "type" attribute is
not provided, software MUST behave as though it were present with a not provided, software MUST behave as though it were present with a
value of "TEXT". value of "TEXT".
Note that MIME media types [RFC2045] are not acceptable values for Note that MIME media types [RFC2045] are not acceptable values for
the "type" attribute. the "type" attribute.
skipping to change at page 8, line 44 skipping to change at page 10, line 8
white-space collapsing, and justification. white-space collapsing, and justification.
If the value of "type" is "HTML", the content of the Text construct If the value of "type" is "HTML", the content of the Text construct
MUST NOT contain child elements, and SHOULD be suitable for handling MUST NOT contain child elements, and SHOULD be suitable for handling
by software that knows HTML. The HTML markup must be escaped; for by software that knows HTML. The HTML markup must be escaped; for
example, "<br>" as "&lt;br>". The HTML markup SHOULD be such that it example, "<br>" as "&lt;br>". The HTML markup SHOULD be such that it
could validly appear directly within an HTML <DIV> element. could validly appear directly within an HTML <DIV> element.
Receiving software which displays the content MAY use the markup to Receiving software which displays the content MAY use the markup to
aid in displaying it. aid in displaying it.
[[example atom entry w/ escaped markup]]
If the value of "type" is "XHTML", the content of the Text construct If the value of "type" is "XHTML", the content of the Text construct
MAY contain child elements. The content SHOULD be XHTML text and MAY contain child elements. The content SHOULD be XHTML text and
markup that could validly appear directly within an xhtml:div markup that could validly appear directly within an xhtml:div
element. Receiving software which displays the content MAY use the element. Receiving software which displays the content MAY use the
markup to aid in displaying it. Escaped markup is interpreted as a markup to aid in displaying it. Escaped markup is interpreted as a
text representation of markup, and MUST NOT be interpreted as markup text representation of markup, and MUST NOT be interpreted as markup
itself. itself.
3.2 Person Constructs 3.2 Person Constructs
A Person construct is an element that describes a person, A Person construct is an element that describes a person,
corporation, or similar entity. corporation, or similar entity.
Person constructs MAY be extended by namespace-qualified element Person constructs MAY be extended by namespace-qualified element
children. children.
This specification assigns no significance to the order of appearance This specification assigns no significance to the order of appearance
of the child elements of a Person construct. of the child elements in a Person construct.
3.2.1 "atom:name" Element atomPersonConstruct =
atomCommonAttributes,
(element atom:name { text }
& element atom:uri { atomUri }?
& element atom:email { atomEmailAddress }?)
3.2.1 The "atom:name" Element
The "atom:name" element's content conveys a human-readable name for The "atom:name" element's content conveys a human-readable name for
the person. Person constructs MUST contain exactly one "atom:name" the person. Person constructs MUST contain exactly one "atom:name"
element. element.
3.2.2 "atom:uri" Element 3.2.2 The "atom:uri" Element
The "atom:uri" element's content conveys a URI associated with the The "atom:uri" element's content conveys a URI associated with the
person. Person constructs MAY contain an atom:uri element, but MUST person. Person constructs MAY contain an atom:uri element, but MUST
NOT contain more than one. The content of atom:uri in a Person NOT contain more than one. The content of atom:uri in a Person
construct MUST be a URI reference [RFC2396bis]. construct MUST be a URI reference [RFC3986].
xml:base [W3C.REC-xmlbase-20010627] processing MUST be applied to the xml:base [W3C.REC-xmlbase-20010627] processing MUST be applied to the
atom:uri element's content. atom:uri element's content.
3.2.3 "atom:email" Element 3.2.3 The "atom:email" Element
The "atom:email" element's content conveys an e-mail address The "atom:email" element's content conveys an e-mail address
associated with the persons. Person constructs MAY contain an associated with the persons. Person constructs MAY contain an
atom:email element, but MUST NOT contain more than one. Its content atom:email element, but MUST NOT contain more than one. Its content
MUST be an e-mail address [RFC2822]. MUST be an e-mail address [RFC2822].
3.3 Date Constructs 3.3 Date Constructs
A Date construct is an element whose content MUST conform to the A Date construct is an element whose content MUST conform to the
date-time BNF rule in [RFC3339]. date-time BNF rule in [RFC3339].
atomDateConstruct =
atomCommonAttributes,
xsd:dateTime
3.4 Service Constructs 3.4 Service Constructs
A Service construct is an empty element that conveys the URI of an A Service construct is an empty element that conveys the URI of an
Atom Publishing Protocol [Atom-protocol] service associated with an Atom Publishing Protocol [Atom-protocol] service associated with an
entry or feed. The type of service is identified by the element entry or feed.
name.
A Service construct has the following attribute: atomServiceConstruct =
atomCommonAttributes,
attribute href { atomUri }
3.4.1 "href" Attribute 3.4.1 The "href" Attribute
The "href" attribute contains the a URI pointing to the endpoint of The "href" attribute contains the a URI of the service. atom:service
the service named by the name attribute. atom:service elements MUST elements MUST have a "href" attribute, whose value MUST be a URI
have a "href" attribute, whose value MUST be a URI reference reference [RFC3986].
[RFC2396bis].
xml:base processing MUST be applied to the "href" attribute. xml:base processing MUST be applied to the "href" attribute.
3.5 Link Constructs 3.5 Identity Constructs
A Link construct is an empty element that describes a connection from
an Atom Document to another Web resource.
3.5.1 "rel" Attribute
Link constructs MAY have an optional "rel" attribute that indicates
the link relation type. If the "rel" attribute is not present, the
link construct MUST be interpreted as if the link relation type is
"alternate".
rel_attribute = segment-nz-nc / URI
The value of "rel" MUST be either a name, which is non-empty and does
not contain any colon (":") characters, or a URI [RFC2396bis]. Note
that use of a relative reference to the "rel" value URI is not
allowed. If a name is given, implementations MUST consider the link
relation type to be equivalent to the same name registered within the
IANA Registry of Link Relations Section 10, and thus the URI that
would be obtained by appending the value of the rel attribute to the
string "http://www.iana.org/assignments/relation/". The value of
"rel" describes the meaning of the link, but does not impose any
behavioral requirements on implementations.
This document defines two initial values for the Registry of Link
Relations:
The value "alternate" signifies that the URI in the value of the href
attribute identifies an alternate version of the resource described
by the containing element.
The value "related" signifies that the URI in the value of the href
attribute identifies a resource to which the resource described by
the containing atom:feed or atom:entry element is related. For
example, the feed for a site which discusses the performance of the
search engine at "http://search.example.com" might contain, as a
child of atom:head:
<link rel="related" href="http://search.example.com/">
An identical link might appear as a child of any atom:entry whose
content contains a discussion of that same search engine.
3.5.2 "type" Attribute
Link constructs MAY have a type attribute, whose value MUST conform
to the syntax of a MIME media type [RFC2045].
The type attribute's value is an advisory media type; it MAY be used
as a hint to determine the type of the representation which is
expected to be returned when the value of the href attribute is
dereferenced. Note that the type attribute does not override the
actual media type returned with the representation.
3.5.3 "href" Attribute
The "href" attribute contains the link's URI. Link constructs MUST
have a href attribute, whose value MUST be a URI reference
[RFC2396bis].
xml:base [W3C.REC-xmlbase-20010627] processing MUST be applied to the
href attribute's content.
3.5.4 "hreflang" Attribute
The "hreflang" attribute's content describes the language of the
resource pointed to by the href attribute. When used together with
the rel="alternate", it implies a translated version of the entry.
Link constructs MAY have an hreflang attribute, whose value MUST be a
language tag [RFC3066].
3.5.5 "title" Attribute
The "title" attribute conveys human-readable information about the
link. Link constructs MAY have a title attribute.
3.5.6 "length" Attribute
The "length" attribute indicates an advisory length of the linked
content in octets; it MAY be used as a hint to determine the content
length of the representation returned when the URI in the href
attribute is dereferenced. Note that the length attribute does not
override the actual content length of the representation as reported
by the underlying protocol.
Link constructs MAY have a length attribute.
3.6 Identity Constructs
An Identity construct is an element whose content conveys a An Identity construct is an element whose content conveys a
permanent, universally unique identifier for the construct's parent. permanent, universally unique identifier for the construct's parent.
Its content MUST be a URI, as defined by [RFC2396bis]. Note that the Its content MUST be a URI, as defined by [RFC3986]. Note that the
definition of "URI" excludes relative references. definition of "URI" excludes relative references.
When an Atom document is relocated, migrated, syndicated, When an Atom document is relocated, migrated, syndicated,
republished, exported or imported, the content of its Identity republished, exported or imported, the content of its Identity
construct MUST NOT change. Put another way, an Identity construct construct MUST NOT change. Put another way, an Identity construct
pertains to all instantiations of a particular Atom entry or feed; pertains to all instantiations of a particular Atom entry or feed;
revisions retain the same content in their Identity constructs. revisions retain the same content in their Identity constructs.
3.6.1 Dereferencing Identity Constructs atomIdentityConstruct =
atomCommonAttributes,
(atomUri)
3.5.1 Dereferencing Identity Constructs
The content of an Identity construct MAY be dereferencable (e.g. an The content of an Identity construct MAY be dereferencable (e.g. an
HTTP URI). However, processors MUST NOT assume it to be HTTP URI). However, processors MUST NOT assume it to be
dereferencable. dereferencable.
The content of an Identity construct MUST be created in a way that The content of an Identity construct MUST be created in a way that
assures uniqueness, and it is suggested that the Identity construct assures uniqueness, and it is suggested that the Identity construct
be stored along with the associated resource. be stored along with the associated resource.
Because of the risk of confusion between URIs that would be Because of the risk of confusion between URIs that would be
skipping to change at page 12, line 47 skipping to change at page 12, line 40
o For schemes that define a default authority, use an empty o For schemes that define a default authority, use an empty
authority if the default is desired. authority if the default is desired.
o For schemes that define an empty path to be equivalent to a path o For schemes that define an empty path to be equivalent to a path
of "/", use "/". of "/", use "/".
o For schemes that define a port, use an empty port if the default o For schemes that define a port, use an empty port if the default
is desired. is desired.
o Preserve empty fragment identifiers and queries. o Preserve empty fragment identifiers and queries.
o Ensure that all portions of the URI are UTF-8 encoded NFC form o Ensure that all portions of the URI are UTF-8 encoded NFC form
Unicode strings. Unicode strings.
3.6.2 Comparing Identity Constructs 3.5.2 Comparing Identity Constructs
Instances of Identity constructs can be compared to determine whether Instances of Identity constructs can be compared to determine whether
an entry or feed is the same as one seen before. Processors MUST an entry or feed is the same as one seen before. Processors MUST
compare Identity constructs on a character-by-character basis in a compare Identity constructs on a character-by-character basis in a
case-sensitive fashion. case-sensitive fashion.
As a result, two URIs that resolve to the same resource but are not As a result, two URIs that resolve to the same resource but are not
character-for-character identical will be considered different for character-for-character identical will be considered different for
the purposes of Identifier comparison. the purposes of Identifier comparison.
For example, "http://www.example.org/thing", For example, "http://www.example.org/thing",
"http://www.example.org/Thing", "http://www.EXAMPLE.org/thing" and "http://www.example.org/Thing", "http://www.EXAMPLE.org/thing" and
"HTTP://www.example.org/thing" will all be considered different "HTTP://www.example.org/thing" will all be considered different
identifiers, despite their differences in case. identifiers, despite their differences in case.
Likewise, "http://www.example.com/~bob", Likewise, "http://www.example.com/~bob",
"http://www.example.com/%7ebob" and "http://www.example.com/%7Ebob" "http://www.example.com/%7ebob" and "http://www.example.com/%7Ebob"
will all be considered different identifiers, because URI %-escaping will all be considered different identifiers, because URI %-escaping
is significant for the purposes of comparison. is significant for the purposes of comparison.
3.7 The Category Construct 4. Element Definitions
Category constructs contain information about a category to which an
Atom feed or entry is associated.
3.7.1 The "term" Attribute
The "term" attribute will be a string which identifies the category
within the categorization scheme to which the entry or feed belongs.
Category constructs MUST have a "term" attribute.
3.7.2 The "scheme" Attribute
The is a URI that identifies a categorization scheme. Category
constructs MAY have a "scheme" attribute.
3.7.3 The "label" attribute
The "label" attribute provides a human-readable label that may be
displayed in end-user applications. Category constructs MAY have a
"label" attribute.
4. The "atom:feed" Element 4.1 The "atom:feed" Element
The "atom:feed" element is the document (i.e., top-level) element of The "atom:feed" element is the document (i.e., top-level) element of
an Atom Feed Document, acting as a container for metadata and data an Atom Feed Document, acting as a container for metadata and data
associated with the feed. Its first element child MUST be atom:head, associated with the feed. Its first element child MUST be atom:head,
which MAY be followed zero or more atom:entry child elements. which MAY be followed zero or more atom:entry child elements.
4.1 "version" Attribute atomFeed =
element atom:feed {
atomCommonAttributes,
atomVersionAttribute,
(atomHead
& atomEntry*
& anyElement*)
}
4.1.1 The "version" Attribute
atom:feed elements MUST have a "version" attribute whose content atom:feed elements MUST have a "version" attribute whose content
indicates the version of the Atom specification that the feed indicates the version of the Atom specification that the feed
conforms to. The content of this attribute is unstructured text. conforms to. The content of this attribute is unstructured text.
The version identifier for this specification is The version identifier for this specification is
"draft-ietf-atompub-format-04 : do not deploy". "draft-ietf-atompub-format-05: do not deploy".
atomVersionAttribute =
attribute version {"draft-ietf-atompub-format-05 : do not deploy"}
4.2 The "atom:head" Element 4.2 The "atom:head" Element
The atom:head element acts as a container for metadata about the feed The atom:head element acts as a container for metadata about the feed
itself. itself.
The atom:head element MAY contain any namespace-qualified The atom:head element MAY contain any namespace-qualified
[W3C.REC-xml-names-19990114] elements as children. This [W3C.REC-xml-names-19990114] elements as children. This
specification assigns no significance to the order of appearance of specification assigns no significance to the order of appearance of
the child elements of atom:head. the child elements of atom:head.
atomHead =
element atom:head {
atomCommonAttributes,
(atomTitle
& atomUpdated
& atomLink+
& atomId?
& atomAuthor?
& atomContributor*
& atomTagline?
& atomGenerator?
& atomInfo?
& atomCopyright?
& atomCategory*
& atomIntrospection?
& atomPost?
& anyElement*)
}
The following child elements are defined by this specification (note The following child elements are defined by this specification (note
that the presence of some of these elements is required): that the presence of some of these elements is required):
4.2.1 "atom:title" Element o atom:head elements MUST contain exactly one atom:title element.
o atom:head elements MUST contain at least one atom:link element
The "atom:title" element is a Text construct that conveys a with a rel attribute value of "alternate".
human-readable title for the feed. atom:head elements MUST contain o atom:head elements MUST NOT contain more than one atom:link
exactly one atom:title element. element with a rel attribute value of "alternate" that has the
same type attribute value. If a feed's atom:link element with
4.2.2 "atom:link" Element type="alternate" resolves to an HTML document, then that document
SHOULD have a autodiscovery link element [Atom-autodiscovery] that
The "atom:link" element is a Link construct that conveys a URI reflects back to the feed. atom:head elements MAY contain
associated with the feed. The nature of the relationship is additional atom:link elements beyond those described above.
determined by the construct's rel attribute. o atom:head elements MUST contain exactly one atom:author element,
UNLESS all of the atom:feed element's child atom:entry elements
contain an atom:author element. atom:head elements MUST NOT
contain more than one atom:author element. [[inheritance]]
o atom:head elements MUST NOT contain more than one an
atom:contributor element.
o atom:head elements MUST NOT contain more than one an
atom:copyright element.
o atom:head elements MUST NOT contain more than one an atom:id
element.
o atom:head elements MUST contain exactly one atom:updated element.
o atom:head elements MAY contain any number of atom:category
elements.
o atom:head elements MUST NOT contain more than one atom:post
element.
atom:head elements MUST contain at least one atom:link element with a o atom:head elements MUST NOT contain more than one
rel attribute value of "alternate". atom:introspection element.
o atom:head elements MUST NOT contain more than one atom:tagline
element.
o atom:head elements MUST NOT contain more than one atom:generator
element.
o atom:head elements MUST NOT contain more than one atom:info
element.
atom:head elements MUST NOT contain more than one atom:link element 4.2.1 Usage of "atom:head" within "atom:entry"
with a rel attribute value of "alternate" that has the same type
attribute value.
If a feed's atom:link element with type="alternate" resolves to an In this case, the atom:head element acts as a container for metadata
HTML document, then that document SHOULD have a autodiscovery link about the feed within which the entry was created.
element [Atom-autodiscovery] that reflects back to the feed.
atom:head elements MAY contain additional atom:link elements beyond If an atom:entry is copied into one feed from another feed, then the
those described above. atom:head element of the source feed SHOULD be inserted into the
atom:entry unless the entry, as copied, already contains an atom:head
element. If the atom:entry already contains an atom:head, then that
atom:head SHOULD be copied without modification.
4.2.3 "atom:category" Element [[ ... example ... ]]
A Category Construct identifying a category with which the feed is 4.3 The "atom:entry" Element
associated. atom:head elements MAY contain any number of
atom:category elements.
4.2.4 "atom:introspection" Element The "atom:entry" element represents an individual entry. This
element can appear as a child of the atom:feed element, or it can
appear as the document (i.e., top-level) element of a standalone Atom
Entry Document.
The "atom:introspection" element is a Service construct that conveys When appearing in an Atom Entry Document, atom:entry elements MUST
the URI of an introspection file associated with the feed. atom:head have a "version" attribute whose content indicates the version of the
elements MUST NOT contain more than one atom:introspection element. Atom specification that the entry conforms to.
4.2.5 "atom:post" Element The version identifier for this specification is
"draft-ietf-atompub-format-05: do not deploy".
The "atom:post" element is a Service construct that conveys the URI The atom:entry element MAY contain any namespace-qualified
used to add entries to the feed. atom:head elements MUST NOT contain [W3C.REC-xml-names-19990114] elements as children. This
more than one atom:post element. specification assigns no significance to the order of appearance of
the child elements of atom:entry.
4.2.6 "atom:author" Element atomEntry =
element atom:entry {
atomCommonAttributes,
atomVersionAttribute?,
(atomTitle
& atomId
& atomLink*
& atomUpdated
& atomPublished?
& atomAuthor?
& atomContributor*
& atomHost?
& atomCopyright?
& atomCategory*
& atomEdit?
& atomSummary?
& atomContent?
& atomHead?
& anyElement*)
}
The "atom:author" element is a Person construct that indicates the The following child elements are defined by this specification (note
default author of the feed. atom:head elements MUST contain exactly that it requires the presence of some of these elements):
one atom:author element, UNLESS all of the atom:feed element's child
atom:entry elements contain an atom:author element. atom:head
elements MUST NOT contain more than one atom:author element.
[[explain inheritance]] o atom:entry elements MUST have exactly one "atom:title" element.
o atom:entry elements MUST contain exactly one atom:id element.
o atom:entry elements that contain no child atom:content element
MUST contain at least one atom:link element with a rel attribute
value of "alternate". atom:entry elements MUST NOT contain more
than one atom:link element with a rel attribute value of
"alternate" that has the same type attribute value. atom:entry
elements MAY contain additional atom:link elements beyond those
described above.
o atom:entry elements MUST contain exactly one atom:updated element.
o atom:entry elements MUST NOT contain more than one atom:published
element.
o atom:entry elements MUST contain exactly one atom:author element,
unless, in an Atom Feed Document, the atom:head element contains
an atom:author element itself. atom:entry elements MUST NOT
contain more than one atom:author element.
o atom:entry elements MUST NOT contain more than one
atom:contributor element.
o atom:entry elements MUST NOT contain more than one atom:host
element.
o atom:entry elements MUST NOT contain more than one atom:copyright
element.
o atom:entry elements MAY contain any number of atom:category
elements.
4.2.7 "atom:contributor" Element o atom:entry elements MUST contain an atom:summary element in any of
the following cases:
* the atom:entry element contains no atom:content element.
* the atom:entry contains an atom:content which has a "src"
attribute (and is thus empty).
* the atom:entry contains content which is encoded in Base64;
i.e. the "type" attribute of atom:content is a MIME media type
[RFC2045] and does not begin with "text/" nor end with "+xml".
o atom:entry elements MUST NOT contain more than one atom:summary
element.
o atom:entry elements MUST NOT contain more than one atom:edit
element.
o atom:entry elements MUST NOT contain more than one atom:head
element.
The "atom:contributor" element is a Person construct that indicates a 4.4 The "atom:title" Element
person or other entity who contributes to the feed. atom:head
elements MAY contain one or more atom:contributor elements.
4.2.8 "atom:tagline" Element The "atom:title" element is a Text construct that conveys a
human-readable title for an entry or feed.
The "atom:tagline" element is a Text construct that conveys a atomTitle = element atom:title { atomTextConstruct }
human-readable description or tagline for the feed. atom:head
elements MAY contain an atom:tagline element, but MUST NOT contain
more than one.
4.2.9 "atom:id" Element 4.5 The "atom:id" Element
The "atom:id" element is an Identity construct that conveys a The "atom:id" element is an Identity construct that conveys a
permanent, universally unique identifier for a feed. atom:head permanent, universally unique identifier for an entry or feed.
elements MAY contain an atom:id element, but MUST NOT contain more
than one.
4.2.10 "atom:generator" Element atomId = element atom:id { atomIdentityConstruct }
The "atom:generator" element's content identifies the software agent 4.6 The "atom:link" Element
used to generate the feed, for debugging and other purposes.
atom:head elements MAY contain an atom:generator element, but MUST
NOT contain more than one.
The content of this element, when present, MUST be a string that is a The atom:link element is an empty element that defines a reference
human-readable name for the generating agent. from an Atom Document to a Web resource.
The atom:generator element MAY have a "uri" attribute whose value atomLink = element atom:link {
MUST be a URI reference [RFC2396bis]. When dereferenced, that URI atomCommonAttributes,
SHOULD produce a representation that is relevant to that agent. attribute href { atomUri },
attribute rel { atomNCName | atomUri }?,
attribute type { atomMediaType }?,
attribute hreflang { atomLanguageTag }?,
attribute title { text }?,
attribute length { text }?,
empty
}
The atom:generator element MAY have a "version" attribute that 4.6.1 The "href" Attribute
indicates the version of the generating agent. When present, its
value is unstructured text.
4.2.11 "atom:copyright" Element The "href" attribute contains the link's URI. Link constructs MUST
have a href attribute, whose value MUST be a URI reference [RFC3986].
The "atom:copyright" element is Text construct that conveys a xml:base [W3C.REC-xmlbase-20010627] processing MUST be applied to the
human-readable copyright statement for the feed. atom:head elements href attribute's content.
MAY contain an atom:copyright element, but MUST NOT contain more than
one.
The atom:copyright element SHOULD NOT be used to convey 4.6.2 The "rel" Attribute
machine-readable licensing information.
4.2.12 "atom:info" Element Link elements MAY have an "rel" attribute that indicates the link
relation type. If the "rel" attribute is not present, the link
element MUST be interpreted as if the link relation type is
"alternate".
The "atom:info" element is a Text construct that conveys a rel_attribute = segment-nz-nc / URI
human-readable explanation of the feed format itself. atom:head
elements MAY contain an atom:info element, but MUST NOT contain more
than one.
The atom:info element SHOULD NOT considered meaningful by processors; The value of "rel" MUST be either a name, which is non-empty and does
it is a convenience to publishers in certain situations. not contain any colon (":") characters, or a URI [RFC3986]. Note
that use of a relative reference is not allowed. If a name is given,
implementations MUST consider the link relation type to be equivalent
to the same name registered within the IANA Registry of Link
Relations Section 9, and thus the URI that would be obtained by
appending the value of the rel attribute to the string
"http://www.iana.org/assignments/relation/". The value of "rel"
describes the meaning of the link, but does not impose any behavioral
requirements on implementations.
4.2.13 "atom:updated" Element This document defines two initial values for the Registry of Link
Relations:
The "atom:updated" element is a Date construct indicating the most The value "alternate" signifies that the URI in the value of the href
recent instant in time when the feed was modified in a way the attribute identifies an alternate version of the resource described
producer considers significant. Therefore, not all modifications by the containing element.
necessarily result in a changed atom:updated value.
atom:head elements MUST contain exactly one atom:updated element. The value "related" signifies that the URI in the value of the href
attribute identifies a resource related to the resource described by
the containing atom:feed or atom:entry element. For example, the
feed for a site which discusses the performance of the search engine
at "http://search.example.com" might contain, as a child of
atom:head:
5. The "atom:entry" Element <link rel="related" href="http://search.example.com/">
An identical link might appear as a child of any atom:entry whose
content contains a discussion of that same search engine.
The "atom:entry" element represents an individual entry. This 4.6.3 The "type" Attribute
element can appear as a child of the atom:feed element, or it can
appear as the document (i.e., top-level) element of a standalone Atom
Entry Document.
When appearing in an Atom Entry Document, atom:entry elements MUST Link elements MAY have a type attribute, whose value MUST conform to
have a "version" attribute whose content indicates the version of the the syntax of a MIME media type [RFC2045].
Atom specification that the entry conforms to.
The version identifier for this specification is The type attribute's value is an advisory media type; it is a hint
"draft-ietf-atompub-format-04 : do not deploy". about the type of the representation which is expected to be returned
when the value of the href attribute is dereferenced. Note that the
type attribute does not override the actual media type returned with
the representation.
The atom:entry element MAY contain any namespace-qualified 4.6.4 The "hreflang" Attribute
[W3C.REC-xml-names-19990114] elements as children. This
specification assigns no significance to the order of appearance of
the child elements of atom:entry.
The following child elements are defined by this specification (note The "hreflang" attribute's content describes the language of the
that it requires the presence of some of these elements): resource pointed to by the href attribute. When used together with
the rel="alternate", it implies a translated version of the entry.
Link elements MAY have an hreflang attribute, whose value MUST be a
language tag [RFC3066].
5.1 "atom:title" Element 4.6.5 The "title" Attribute
The "atom:title" element is a Text construct that conveys a The "title" attribute conveys human-readable information about the
human-readable title for the entry. atom:entry elements MUST have link. Link elements MAY have a title attribute.
exactly one "atom:title" element.
5.2 "atom:link" Element 4.6.6 The "length" Attribute
The "atom:link" element is a Link construct that conveys a URI The "length" attribute indicates an advisory length of the linked
associated with the entry. The nature of the relationship as well as content in octets; it is a hint about the content length of the
the link itself is determined by the element's content. representation returned when the URI in the href attribute is
dereferenced. Note that the length attribute does not override the
actual content length of the representation as reported by the
underlying protocol.
atom:entry elements that contain no child atom:content element MUST Link elements MAY have a length attribute.
contain at least one atom:link element with a rel attribute value of
"alternate".
atom:entry elements MUST NOT contain more than one atom:link element 4.7 The "atom:updated" Element
with a rel attribute value of "alternate" that has the same type
attribute value.
atom:entry elements MAY contain additional atom:link elements beyond The "atom:updated" element is a Date construct indicating the most
those described above. recent instant in time when an entry or feed was modified in a way
the producer considers significant. Therefore, not all modifications
necessarily result in a changed atom:updated value.
5.3 "atom:category" Element Publishers MAY change the value of this element over time.
Processors MAY present entries sorted using this value. Processors
MAY choose not to present entries until the instant in time specified
in the atom:updated element has passed.
A Category Construct identifying a category with which the entry is atomUpdated = element atom:updated { atomDateConstruct }
associated. atom:entry elements MAY contain any number of
atom:category elements.
5.4 "atom:edit" Element 4.8 The "atom:published" Element
The "atom:edit" element is a Service construct that conveys the URI The "atom:published" element is a Date construct indicating an
used to retrieve and edit the source representation of the entry. instant in time associated with an event early in the life cycle of
atom:entry elements MUST NOT contain more than one atom:edit element. the entry. Typically, atom:published will be associated with the
initial creation or first availability of the resource.
5.5 "atom:author" Element Processors MAY present entries sorted using this value. Processors
MAY choose not to present entries until the instant in time specified
in the atom:published element has passed.
4.9 The "atom:author" Element
The "atom:author" element is a Person construct that indicates the The "atom:author" element is a Person construct that indicates the
default author of the entry. atom:entry elements MUST contain default author of the an entry or feed
exactly one atom:author element, unless, in an Atom Feed Document,
the atom:head element contains an atom:author element itself.
atom:entry elements MUST NOT contain more than one atom:author
element.
5.6 "atom:contributor" Element atomAuthor = element atom:author { atomPersonConstruct }
4.10 The "atom:contributor" Element
The "atom:contributor" element is a Person construct that indicates a The "atom:contributor" element is a Person construct that indicates a
person or other entity who contributes to the entry. atom:entry person or other entity who contributes to the entry.
elements MAY contain one or more atom:contributor elements.
5.7 "atom:host" Element atomContributor = element atom:contributor { atomPersonConstruct }
4.11 The "atom:host" Element
The "atom:host" element's content conveys a domain name or network The "atom:host" element's content conveys a domain name or network
address associated with the entry's origin. atom:entry elements MAY address associated with an entry's origin. Its content MUST be a
contain a single atom:host element. Its content MUST be a domain domain name [RFC1035], a dotted-decimal IPv4 address [RFC0791], or a
name [RFC1035], a dotted-decimal IPv4 address [RFC0791], or a
colon-delimited IPv6 address [RFC2460]. colon-delimited IPv6 address [RFC2460].
5.8 "atom:id" Element 4.12 The "atom:copyright" Element
The "atom:id" element is an Identity construct that conveys a The "atom:copyright" element is a Text construct that conveys a
permanent, universally unique identifier for an entry. atom:entry human-readable copyright statement for an entry or feed.
elements MUST contain exactly one atom:id element.
5.9 "atom:updated" Element The atom:copyright element SHOULD NOT be used to convey
machine-readable licensing information.
The "atom:updated" element is a Date construct indicating the most If an atom:entry element does not contain an atom:copyright element,
recent instant in time when the entry was modified in a way the then the atom:copyright element of the containing atom:feed element's
producer considers significant. Therefore, not all modifications atom:head element, if present, should be considered to apply to the
necessarily result in a changed atom:updated value. entry.
atom:entry elements MUST contain exactly one atom:updated element. 4.13 The "atom:category" Element
Publishers MAY change the value of this element over time. Category elements contain information about a category to which an
Atom feed or entry is associated.
Processors MAY present entries sorted using this value. Processors atomCategory = element atom:category {
MAY choose not to present entries until the instant in time specified atomCommonAttributes,
in the atom:updated element has passed. attribute term { text },
attribute scheme { atomUri }?,
attribute label { text }?,
empty
}
5.10 "atom:published" Element 4.13.1 The "term" Attribute
The "atom:published" element is a Date construct indicating an The "term" attribute is a string which identifies the category to
instant in time associated with an event early in the life cycle of which the entry or feed belongs. Category elements MUST have a
the entry. Typically, atom:published will be associated with the "term" attribute.
initial creation or first availability of the resource.
atom:entry elements MAY contain an atom:published element, but MUST 4.13.2 The "scheme" Attribute
NOT contain more than one.
Processors MAY present entries sorted using this value. Processors The "scheme" attribute is a URI that identifies a categorization
MAY choose not to present entries until the instant in time specified scheme. Category elements MAY have a "scheme" attribute.
in the atom:published element has passed.
5.11 "atom:summary" Element 4.13.3 The "label" attribute
The "atom:summary" element is a Text construct that conveys a short The "label" attribute provides a human-readable label that may be
summary, abstract or excerpt of the entry. atom:entry elements MAY displayed in end-user applications. Category elements MAY have a
contain an atom:summary element, but MUST NOT contain more than one. "label" attribute.
atom:entry elements MUST contain an atom:summary element in any of 4.14 The "atom:summary" Element
the following cases:
o the atom:entry element contains no atom:content element. The "atom:summary" element is a Text construct that conveys a short
o the atom:entry contains an atom:content which has a "src" summary, abstract or excerpt of an entry.
attribute (and is thus empty).
o the atom:entry contains content which is encoded in Base64; i.e.
the "type" attribute of atom:content is a MIME media type
[RFC2045] and does not begin with "text/" nor end with "+xml".
5.12 "atom:content" Element atomSummary = element atom:summary { atomTextConstruct }
4.15 The "atom:content" Element
The "atom:content" element either contains or links to the content of The "atom:content" element either contains or links to the content of
the entry. atom:entry elements MUST contain zero or one atom:content the entry. atom:entry elements MUST contain zero or one atom:content
elements. elements.
5.12.1 "type" attribute atomInlineTextContent =
element atom:content {
atomCommonAttributes,
attribute type { "TEXT" | "HTML" | atomMediaType }?,
(text)*
}
atomInlineXHTMLContent =
element atom:content {
atomCommonAttributes,
attribute type { "XHTML" | atomMediaType }?,
(text|anyElement)*
}
atomOutOfLineContent =
element atom:content {
atomCommonAttributes,
attribute type { "TEXT" | "HTML" | "XHTML" | atomMediaType }?,
attribute src { atomUri },
empty
}
atomContent = atomInlineTextContent
| atomInlineXHTMLContent
| atomOutOfLineContent
4.15.1 The "type" attribute
atom:content MAY have a "type" attribute, When present, the value MAY atom:content MAY have a "type" attribute, When present, the value MAY
be one of "TEXT", "HTML", or "XHTML". Failing that, it MUST be a be one of "TEXT", "HTML", or "XHTML". Failing that, it MUST be a
MIME media type [RFC2045] in which, to use the terminology of Section MIME media type [RFC2045] in which, to use the terminology of Section
5 of [RFC2045], the top level is a discrete type. If the type 5 of [RFC2045], the top level is a discrete type. If the type
attribute is not provided, software MUST behave as though it were attribute is not provided, software MUST behave as though it were
present with a value of "TEXT". present with a value of "TEXT".
5.12.2 "src" attribute 4.15.2 The "src" attribute
atom:content MAY have a "src" attribute, whose value MUST be a URI atom:content MAY have a "src" attribute, whose value MUST be a URI
reference [RFC2396bis]. If the "src" attribute is present, software reference [RFC3986]. If the "src" attribute is present, software MAY
MAY use the URI to retrieve the content. If the "src" attribute is use the URI to retrieve the content. If the "src" attribute is
present, atom:content MUST be empty. That is to say, the content may present, atom:content MUST be empty. That is to say, the content may
be retrievable using "src=" URI, or it may be contained within be retrievable using "src=" URI, or it may be contained within
atom:content, but not both. atom:content, but not both.
If the "src" attribute is present, the "type" attribute SHOULD be If the "src" attribute is present, the "type" attribute SHOULD be
provided and MUST be a MIME media type [RFC2045], rather than "TEXT", provided and MUST be a MIME media type [RFC2045], rather than "TEXT",
"HTML", or "XHTML". The value is advisory; that is to say, upon "HTML", or "XHTML". The value is advisory; that is to say, upon
dereferencing the URI to retrieve the content, if the server dereferencing the URI to retrieve the content, if the server
providing that content also provides a media type, the providing that content also provides a media type, the
server-provided media type is authoritative. server-provided media type is authoritative.
If the value of type begins with "text/" or ends with "+xml", the If the value of type begins with "text/" or ends with "+xml", the
content SHOULD be local; that is to say, no "src" attribute should be content SHOULD be local; that is to say, no "src" attribute should be
provided. provided.
5.12.3 Processing Model 4.15.3 Processing Model
Software MUST apply the following rules in succession in the order Software MUST apply the following rules in the order below to
below to ascertain the rules governing the content of "atom:content". ascertain the rules governing the content of "atom:content".
1. If the value is "TEXT", the content of atom:content MUST NOT 1. If the value is "TEXT", the content of atom:content MUST NOT
contain child elements. Such text is intended to be presented to contain child elements. Such text is intended to be presented to
humans in a readable fashion. Thus, software MAY display it humans in a readable fashion. Thus, software MAY display it
using normal text rendering techniques such as proportional using normal text rendering techniques such as proportional
fonts, white-space collapsing, and justification. fonts, white-space collapsing, and justification.
2. If the value of "type" is "HTML", the content of atom:content 2. If the value of "type" is "HTML", the content of atom:content
MUST NOT contain child elements, and SHOULD be suitable for MUST NOT contain child elements, and SHOULD be suitable for
handling by software that knows HTML. The HTML markup must be handling by software that knows HTML. The HTML markup must be
escaped; for example, "<br>" as "&lt;br>". The HTML markup escaped; for example, "<br>" as "&lt;br>". The HTML markup
skipping to change at page 22, line 9 skipping to change at page 25, line 4
interpreted as markup itself. interpreted as markup itself.
4. If the value of "type" ends with "+xml" or "/xml", the content of 4. If the value of "type" ends with "+xml" or "/xml", the content of
atom:content may include child elements, and SHOULD be suitable atom:content may include child elements, and SHOULD be suitable
for handling by software that knows the indicated media type. If for handling by software that knows the indicated media type. If
the "src" attribute is not provided, this would normally mean the "src" attribute is not provided, this would normally mean
that the "atom:content" element would contain a single child that the "atom:content" element would contain a single child
element which would serve as the root element of the XML document element which would serve as the root element of the XML document
of the indicated type. of the indicated type.
5. If the value of "type" begins with "text/" the content of 5. If the value of "type" begins with "text/" the content of
atom:content MUST NOT contain child elements. atom:content MUST NOT contain child elements.
6. For all other values of "type", the content of atom:content MUST 6. For all other values of "type", the content of atom:content MUST
be a valid Base64 encoding [RFC3548], which when decoded SHOULD be a valid Base64 encoding [RFC3548], which when decoded SHOULD
be suitable for handling by software that knows the indicated be suitable for handling by software that knows the indicated
media type. In this case, the characters in the Base64 encoding media type. In this case, the characters in the Base64 encoding
may be preceded and followed in the atom:content element by may be preceded and followed in the atom:content element by
whitespace, and lines are separated by a single newline (U+000A) whitespace, and lines are separated by a single newline (U+000A)
character, as required by XML. character.
5.13 "atom:copyright" Element 4.16 The "atom:introspection" Element
The "atom:copyright" element is a Text construct that conveys a The "atom:introspection" element is a Service construct that conveys
human-readable copyright statement for the entry. atom:entry the URI of an introspection file associated with a feed.
elements MAY contain an atom:copyright element, but MUST NOT contain
more than one.
The atom:copyright element SHOULD NOT be used to convey atomIntrospection =
machine-readable licensing information. element atom:introspection { atomServiceConstruct }
If an atom:entry element does not contain an atom:copyright element, 4.17 The "atom:post" Element
then the atom:copyright element of the containing atom:feed element's
atom:head element, if present, should be considered to apply to the
entry.
5.14 "atom:head" Element The "atom:post" element is a Service construct that conveys the URI
used to add entries to a feed.
The atom:head element acts as a container for metadata about the feed atomPost = element atom:post { atomServiceConstruct }
within which the entry was created.
atom:entry elements MAY contain at most one atom:head element. If 4.18 The "atom:edit" Element
the atom:head element is present, it SHOULD be the first child
element of atom:entry.
If an atom:entry is copied into one feed from another feed, then the The "atom:edit" element is a Service construct that conveys the URI
atom:head element of the source feed SHOULD be inserted into the used to retrieve and edit the source representation of an entry.
atom:entry unless the entry, as copied, already contains an atom:head
element. If the atom:entry already contains an atom:head, then that
atom:head SHOULD be copied without modification.
[[ ... example ... ]] atomEdit = element atom:edit { atomServiceConstruct }
6. Managing Feed State 4.19 The "atom:tagline" Element
The "atom:tagline" element is a Text construct that conveys a
human-readable description or tagline for the feed.
atomTagline = element atom:tagline { atomTextConstruct }
4.20 The "atom:generator" Element
The "atom:generator" element's content identifies the software agent
used to generate a feed, for debugging and other purposes.
atomGenerator = element atom:generator {
atomCommonAttributes,
attribute url { atomUri }?,
attribute version { text }?,
text
}
The content of this element, when present, MUST be a string that is a
human-readable name for the generating agent.
The atom:generator element MAY have a "uri" attribute whose value
MUST be a URI reference [RFC3986]. When dereferenced, that URI
SHOULD produce a representation that is relevant to that agent.
The atom:generator element MAY have a "version" attribute that
indicates the version of the generating agent. When present, its
value is unstructured text.
4.21 The "atom:info" Element
The "atom:info" element is a Text construct that conveys a
human-readable explanation of the feed format itself. The atom:info
element SHOULD NOT be considered meaningful by processors; it is a
convenience to publishers.
atomInfo = element atom:info { atomTextConstruct }
5. Managing Feed State
[[ talk about what it means to keep a view of a feed ]] [[ talk about what it means to keep a view of a feed ]]
7. Securing Atom Documents 6. Securing Atom Documents
Because Atom is an XML-based format, existing XML security mechanisms Because Atom is an XML-based format, existing XML security mechanisms
can be used to secure its content. can be used to secure its content.
Note that while these mechanisms are available to secure Atom 6.1 Digital Signatures
documents, they should not be used indiscriminately.
7.1 Digital Signatures
The document element of an Atom document (i.e., atom:feed in an Atom The document element of an Atom document (i.e., atom:feed in an Atom
Feed Document, atom:entry in an Atom Entry Document) MAY have an Feed Document, atom:entry in an Atom Entry Document) MAY have an
Enveloped Signature, as described by XML-Signature and Syntax Enveloped Signature, as described by XML-Signature and Syntax
Processing [W3C.REC-xmldsig-core-20020212]. Other XML signature Processing [W3C.REC-xmldsig-core-20020212].
mechanisms MUST NOT be used on the document element of an Atom
document.
Processors MUST NOT reject an Atom document containing such a Processors MUST NOT reject an Atom document containing such a
signature because they are not capable of verifying it; they MUST signature because they are not capable of verifying it; they MUST
continue processing and MAY inform the user of their failure to continue processing and MAY inform the user of their failure to
validate the signature. validate the signature.
In other words, the presence of an element with the namespace URI In other words, the presence of an element with the namespace URI
"http://www.w3.org/2000/09/xmldsig#" and a local name of "Signature" "http://www.w3.org/2000/09/xmldsig#" and a local name of "Signature"
as a child of the document element must not cause a processor to fail as a child of the document element must not cause a processor to fail
merely because of its presence. merely because of its presence.
Other elements in an Atom document MUST NOT be signed unless their Other elements in an Atom document MUST NOT be signed unless their
definitions explicitly specify such a capability. definitions explicitly specify such a capability.
7.2 Encryption 6.2 Encryption
The document element of an Atom document (i.e., atom:feed in an Atom The document element of an Atom document (i.e., atom:feed in an Atom
Feed Document, atom:entry in an Atom Entry Document) MAY be Feed Document, atom:entry in an Atom Entry Document) MAY be
encrypted, using the mechanisms described by XML Encryption Syntax encrypted, using the mechanisms described by XML Encryption Syntax
and Processing [W3C.REC-xmlenc-core-20021210]. Other XML encryption and Processing [W3C.REC-xmlenc-core-20021210].
mechanisms MUST NOT be used on the document element of an Atom
document.
8. Embedding Atom in Other Formats 7. Embedding Atom in Other Formats
[[ ... ]] [[ ... ]]
9. Extending Atom 8. Extending Atom
[[ ... ]] [[ ... ]]
10. IANA Considerations 9. IANA Considerations
An Atom Document, when serialized as XML 1.0, can be identified with An Atom Document, when serialized as XML 1.0, can be identified with
the following media type: the following media type:
MIME media type name: application MIME media type name: application
MIME subtype name: atom+xml MIME subtype name: atom+xml
Mandatory parameters: None. Mandatory parameters: None.
Optional parameters: Optional parameters:
"charset": This parameter has identical semantics to the charset "charset": This parameter has identical semantics to the charset
parameter of the "application/xml" media type as specified in parameter of the "application/xml" media type as specified in
skipping to change at page 27, line 46 skipping to change at page 31, line 46
Fragment identifiers: As specified for "application/xml" in RFC 3023 Fragment identifiers: As specified for "application/xml" in RFC 3023
[RFC3023], section 5. [RFC3023], section 5.
Base URI: As specified in RFC 3023 [RFC3023], section 6. Base URI: As specified in RFC 3023 [RFC3023], section 6.
Macintosh File Type code: TEXT Macintosh File Type code: TEXT
Person and email address to contact for further information: Mark Person and email address to contact for further information: Mark
Nottingham <mnot@pobox.com> Nottingham <mnot@pobox.com>
Intended usage: COMMON Intended usage: COMMON
Author/Change controller: This specification's author(s). [[update Author/Change controller: This specification's author(s). [[update
upon publication]] upon publication]]
10.1 Registry of Link Relations 9.1 Registry of Link Relations
This registry is maintained by IANA and initially contains the two This registry is maintained by IANA and initially contains the two
values: "alternate" and "related". New assignments are subject to values: "alternate" and "related". New assignments are subject to
IESG Approval, as outlined in [RFC2434]. Requests should be made by IESG Approval, as outlined in [RFC2434]. Requests should be made by
email to IANA, which will then forward the request to the IESG email to IANA, which will then forward the request to the IESG
requesting approval. The request should contain discussion of at requesting approval. The request should contain discussion of at
least the following five topics: least the following five topics:
o A value for the "rel" attribute that conforms to the syntax rule o A value for the "rel" attribute that conforms to the syntax rule
given in Section 3.5.1 given in Section 4.6.2
o Common name for link type. o Common name for link type.
o Description of link type semantics. o Description of link type semantics.
o Expected display characteristics. o Expected display characteristics.
o Security considerations. o Security considerations.
11. Security Considerations 10. Security Considerations
Atom document can be encrypted and signed using Atom document can be encrypted and signed using
[W3C.REC-xmlenc-core-20021210] and [W3C.REC-xmldsig-core-20020212], [W3C.REC-xmlenc-core-20021210] and [W3C.REC-xmldsig-core-20020212],
respectively, and is subject to the security considerations implied respectively, and is subject to the security considerations implied
by their use. by their use.
12. References 11. References
12.1 Normative References 11.1 Normative References
[Atom-autodiscovery] [Atom-autodiscovery]
Pilgrim, M., "Atom Feed Autodiscovery", work-in-progress, Pilgrim, M., "Atom Feed Autodiscovery", work-in-progress,
August 2004. August 2004.
[Atom-protocol] [Atom-protocol]
Gregorio, J. and R. Sayre, "The Atom Publishing Protocol", Gregorio, J. and R. Sayre, "The Atom Publishing Protocol",
work-in-progress, July 2004. work-in-progress, July 2004.
[RFC0791] Postel, J., "Internet Protocol", STD 5, RFC 791, September [RFC0791] Postel, J., "Internet Protocol", STD 5, RFC 791, September
skipping to change at page 30, line 30 skipping to change at page 34, line 30
[RFC1035] Mockapetris, P., "Domain names - implementation and [RFC1035] Mockapetris, P., "Domain names - implementation and
specification", STD 13, RFC 1035, November 1987. specification", STD 13, RFC 1035, November 1987.
[RFC2045] Freed, N. and N. Borenstein, "Multipurpose Internet Mail [RFC2045] Freed, N. and N. Borenstein, "Multipurpose Internet Mail
Extensions (MIME) Part One: Format of Internet Message Extensions (MIME) Part One: Format of Internet Message
Bodies", RFC 2045, November 1996. Bodies", RFC 2045, November 1996.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997. Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2396bis]
Berners-Lee, T., Fielding, R. and L. Masinter, "Uniform
Resource Identifier (URI): Generic Syntax", awaiting RFC
number, December 2004.
[RFC2460] Deering, S. and R. Hinden, "Internet Protocol, Version 6 [RFC2460] Deering, S. and R. Hinden, "Internet Protocol, Version 6
(IPv6) Specification", RFC 2460, December 1998. (IPv6) Specification", RFC 2460, December 1998.
[RFC2822] Resnick, P., "Internet Message Format", RFC 2822, April [RFC2822] Resnick, P., "Internet Message Format", RFC 2822, April
2001. 2001.
[RFC3023] Murata, M., St. Laurent, S. and D. Kohn, "XML Media [RFC3023] Murata, M., St. Laurent, S. and D. Kohn, "XML Media
Types", RFC 3023, January 2001. Types", RFC 3023, January 2001.
[RFC3066] Alvestrand, H., "Tags for the Identification of [RFC3066] Alvestrand, H., "Tags for the Identification of
Languages", BCP 47, RFC 3066, January 2001. Languages", BCP 47, RFC 3066, January 2001.
[RFC3339] Klyne, G. and C. Newman, "Date and Time on the Internet: [RFC3339] Klyne, G. and C. Newman, "Date and Time on the Internet:
Timestamps", RFC 3339, July 2002. Timestamps", RFC 3339, July 2002.
[RFC3548] Josefsson, S., "The Base16, Base32, and Base64 Data [RFC3548] Josefsson, S., "The Base16, Base32, and Base64 Data
Encodings", RFC 3548, July 2003. Encodings", RFC 3548, July 2003.
[RFC3986] Berners-Lee, T., Fielding, R. and L. Masinter, "Uniform
Resource Identifier (URI): Generic Syntax", STD 66, RFC
3986, January 2005.
[W3C.NOTE-datetime-19980827] [W3C.NOTE-datetime-19980827]
Wolf, M. and C. Wicksteed, "Date and Time Formats", W3C Wolf, M. and C. Wicksteed, "Date and Time Formats", W3C
NOTE NOTE-datetime-19980827, August 1998. NOTE NOTE-datetime-19980827, August 1998.
[W3C.REC-xml-20040204] [W3C.REC-xml-20040204]
Yergeau, F., Paoli, J., Sperberg-McQueen, C., Bray, T. and Yergeau, F., Paoli, J., Sperberg-McQueen, C., Bray, T. and
E. Maler, "Extensible Markup Language (XML) 1.0 (Third E. Maler, "Extensible Markup Language (XML) 1.0 (Third
Edition)", W3C REC REC-xml-20040204, February 2004. Edition)", W3C REC REC-xml-20040204, February 2004.
[W3C.REC-xml-infoset-20011024] [W3C.REC-xml-infoset-20011024]
skipping to change at page 31, line 36 skipping to change at page 35, line 34
[W3C.REC-xmldsig-core-20020212] [W3C.REC-xmldsig-core-20020212]
Solo, D., Reagle, J. and D. Eastlake, "XML-Signature Solo, D., Reagle, J. and D. Eastlake, "XML-Signature
Syntax and Processing", W3C REC REC-xmldsig-core-20020212, Syntax and Processing", W3C REC REC-xmldsig-core-20020212,
February 2002. February 2002.
[W3C.REC-xmlenc-core-20021210] [W3C.REC-xmlenc-core-20021210]
Reagle, J. and D. Eastlake, "XML Encryption Syntax and Reagle, J. and D. Eastlake, "XML Encryption Syntax and
Processing", W3C REC REC-xmlenc-core-20021210, December Processing", W3C REC REC-xmlenc-core-20021210, December
2002. 2002.
12.2 Informative References 11.2 Informative References
[RELAX-NG]
OASIS Technical Committee: RELAX NG, "RELAX NG
Specification", December 2001.
[RFC2434] Narten, T. and H. Alvestrand, "Guidelines for Writing an [RFC2434] Narten, T. and H. Alvestrand, "Guidelines for Writing an
IANA Considerations Section in RFCs", BCP 26, RFC 2434, IANA Considerations Section in RFCs", BCP 26, RFC 2434,
October 1998. October 1998.
URIs URIs
[1] <http://www.imc.org/atom-syntax/index.html> [1] <http://www.imc.org/atom-syntax/index.html>
[2] <http://www.intertwingly.net/wiki/pie/FrontPage> [2] <http://www.intertwingly.net/wiki/pie/FrontPage>
skipping to change at page 33, line 8 skipping to change at page 37, line 8
Robert Sayre (editor) Robert Sayre (editor)
Boswijck Memex Consulting Boswijck Memex Consulting
EMail: rfsayre@boswijck.com EMail: rfsayre@boswijck.com
URI: http://boswijck.com URI: http://boswijck.com
Appendix A. Contributors Appendix A. Contributors
The following people contributed to preliminary drafts of this The following people contributed to preliminary drafts of this
document: Tim Bray, Mark Pilgrim, and Sam Ruby. The content and document: Tim Bray, Mark Pilgrim, and Sam Ruby. Norman Walsh
concepts within are a product of the Atom community and the Atom provided the Relax NG schema. The content and concepts within are a
Publishing Format and Protocol Working Group. product of the Atom community and the Atom Publishing Format and
Protocol Working Group.
Appendix B. Revision History Appendix B. Collected RELAX NG Compact Schema
This appendix is informative.
# -*- Relax NG -*-
namespace local = ""
namespace atom =
"http://purl.org/atom/ns#draft-ietf-atompub-format-04"
namespace s = "http://www.ascc.net/xml/schematron"
start = atomFeed | atomEntry
# Attribute definitions
atomCommonAttributes =
attribute xml:base { atomUri }?,
attribute xml:lang { atomLanguageTag }?
atomVersionAttribute =
attribute version {"draft-ietf-atompub-format-05 : do not deploy"}
# Common Atom Constructs
atomPlainTextConstruct =
atomCommonAttributes,
attribute type { "TEXT" | "HTML" }?,
text
atomXHTMLTextConstruct =
atomCommonAttributes,
attribute type { "XHTML" },
(text|anyElement)*
atomTextConstruct = atomPlainTextConstruct | atomXHTMLTextConstruct
atomPersonConstruct =
atomCommonAttributes,
(element atom:name { text }
& element atom:uri { atomUri }?
& element atom:email { atomEmailAddress }?)
atomDateConstruct =
atomCommonAttributes,
xsd:dateTime
atomServiceConstruct =
atomCommonAttributes,
attribute href { atomUri }
atomIdentityConstruct =
atomCommonAttributes,
(atomUri)
# atom:feed
# TODO: Test for multiple atom:link/@rel='alternate' with
# the same @type The following tests are simple to do,
# but my validator is giving me trouble.
# TODO: Debug and add them back
# Test for at least one atom:link/@rel='alternate'
# Test for atom:author or all atom:entry have atom:author
# atom:feed
atomFeed =
element atom:feed {
atomCommonAttributes,
atomVersionAttribute,
(atomHead
& atomEntry*
& anyElement*)
}
# atom:head
atomHead =
[
s:rule [
context = "atom:head"
s:assert [
test = "atom:link[@rel='alternate']"
"An atom:feed must have at least one link element
with a rel attribute of 'alternate'."
]
]
s:rule [
context = "atom:head"
s:assert [
test = "atom:author or not(../atom:entry[count(atom:author) = 0])"
"An atom:feed must have an atom:author unless all of
its atom:entry children have an atom:author."
]
]
]
element atom:head {
atomCommonAttributes,
(atomTitle
& atomUpdated
& atomLink+
& atomId?
& atomAuthor?
& atomContributor*
& atomTagline?
& atomGenerator?
& atomInfo?
& atomCopyright?
& atomCategory*
& atomIntrospection?
& atomPost?
& anyElement*)
}
# atom:entry
# TODO: Test for multiple atom:link @rel='alternate'
# with the same @type
# TODO: Test for required atom:summary
atomEntry =
[
s:rule [
context = "/atom:entry"
s:assert [
test = "@version"
"The version attribute is required on standalone
atom:entry elements."
]
]
s:rule [
context = "atom:entry"
s:assert [
test = "atom:link[@rel='alternate']"
"An atom:entry must have at least one link element
with a rel attribute of 'alternate'."
]
]
s:rule [
context = "atom:entry"
s:assert [
test = "atom:author or ../atom:author"
"An atom:entry must have an atom:author
if the parent atom:feed does not."
]
]
]
element atom:entry {
atomCommonAttributes,
atomVersionAttribute?,
(atomTitle
& atomId
& atomLink*
& atomUpdated
& atomPublished?
& atomAuthor?
& atomContributor*
& atomHost?
& atomCopyright?
& atomCategory*
& atomEdit?
& atomSummary?
& atomContent?
& atomHead?
& anyElement*)
}
# atom:title
atomTitle = element atom:title { atomTextConstruct }
# atom:id
atomId = element atom:id { atomIdentityConstruct }
atomLink = element atom:link {
atomCommonAttributes,
attribute href { atomUri },
attribute rel { atomNCName | atomUri }?,
attribute type { atomMediaType }?,
attribute hreflang { atomLanguageTag }?,
attribute title { text }?,
attribute length { text }?,
empty
}
# atom:updated
# TODO: Test for a timezone that SHOULD be UTC
atomUpdated = element atom:updated { atomDateConstruct }
# atom:published
atomPublished = element atom:published { atomDateConstruct }
# atom:author
atomAuthor = element atom:author { atomPersonConstruct }
# atom:contributor
atomContributor = element atom:contributor { atomPersonConstruct }
# atom:host
# TODO: tighten this up
atomHost = element atom:host { text }
# atom:copyright
atomCopyright = element atom:copyright { atomTextConstruct }
# atom:category
atomCategory = element atom:category {
atomCommonAttributes,
attribute term { text },
attribute scheme { atomUri }?,
attribute label { text }?,
empty
}
# atom:summary
atomSummary = element atom:summary { atomTextConstruct }
# atom:content
atomInlineTextContent =
element atom:content {
atomCommonAttributes,
attribute type { "TEXT" | "HTML" | atomMediaType }?,
(text)*
}
atomInlineXHTMLContent =
element atom:content {
atomCommonAttributes,
attribute type { "XHTML" | atomMediaType }?,
(text|anyElement)*
}
atomOutOfLineContent =
element atom:content {
atomCommonAttributes,
attribute type { "TEXT" | "HTML" | "XHTML" | atomMediaType }?,
attribute src { atomUri },
empty
}
atomContent = atomInlineTextContent
| atomInlineXHTMLContent
| atomOutOfLineContent
# atom:introspection
atomIntrospection =
element atom:introspection { atomServiceConstruct }
# atom:post
atomPost = element atom:post { atomServiceConstruct }
# atom:edit
atomEdit = element atom:edit { atomServiceConstruct }
# atom:tagline
atomTagline = element atom:tagline { atomTextConstruct }
# atom:generator
atomGenerator = element atom:generator {
atomCommonAttributes,
attribute url { atomUri }?,
attribute version { text }?,
text
}
# atom:info
atomInfo = element atom:info { atomTextConstruct }
# Low-level simple types
# TODO: can anything more specific be said about these types?
atomNCName = xsd:string { minLength = "1" pattern = "[^:]*" }
atomMediaType = text
atomLanguageTag = text
atomUri = text
atomEmailAddress = text
# Extensibility
anyForeignElement =
element * - (atom:* | local:*)
{
(attribute * { text }
| text
| anyForeignElement)*
}
anyForeignAttribute =
attribute * - (atom:* | local:* | xml:*) { text }
anyElement =
element * - atom:*
{
(attribute * { text }
| text
| anyElement)*
}
# EOF
Appendix C. Revision History
[[ this section should be removed before final publication. ]] [[ this section should be removed before final publication. ]]
-05: Add RNC from N. Walsh.
Re-organize element definitions.
Lift the prohibition on other types of DSig and encryption.
Remove text on "indiscriminate use" of DSig and XMLEnc.
-04: Update URI terms for 2396bis. -04: Update URI terms for 2396bis.
Add Category construct (PaceCategoryRevised). Add Category construct (PaceCategoryRevised).
Insert paranoid XHTML interpretation guidelines. Insert paranoid XHTML interpretation guidelines.
Adjust atom:copyright, per chairs' instruction. Adjust atom:copyright, per chairs' instruction.
Add atom:host as child element of atom:entry, per chairs' Add atom:host as child element of atom:entry, per chairs'
direction (PacePersonConstruct). direction (PacePersonConstruct).
Add link/content co-constraint (PaceContentOrLink). Add link/content co-constraint (PaceContentOrLink).
Remove atom:origin as a side effect of adding atom:head to Remove atom:origin as a side effect of adding atom:head to
atom:entry (PaceHeadInEntry). atom:entry (PaceHeadInEntry).
Add optional length attribute to atom:link (PaceLinkRelated). Add optional length attribute to atom:link (PaceLinkRelated).
 End of changes. 

This html diff was produced by rfcdiff 1.23, available from http://www.levkowetz.com/ietf/tools/rfcdiff/