draft-ietf-atompub-format-06.txt		draft-ietf-atompub-format-07.txt
	Network Working Group M. Nottingham, Ed.		Network Working Group M. Nottingham, Ed.
	Internet-Draft		Internet-Draft R. Sayre, Ed.
	Expires: September 13, 2005 R. Sayre, Ed.		Expires: October 2, 2005 March 31, 2005
	Boswijck Memex Consulting
	March 12, 2005
	The Atom Syndication Format		The Atom Syndication Format
	draft-ietf-atompub-format-06		draft-ietf-atompub-format-07
	Status of this Memo		Status of this Memo
	This document is an Internet-Draft and is subject to all provisions		This document is an Internet-Draft and is subject to all provisions
	of Section 3 of RFC 3667. By submitting this Internet-Draft, each		of Section 3 of RFC 3667. By submitting this Internet-Draft, each
	author represents that any applicable patent or other IPR claims of		author represents that any applicable patent or other IPR claims of
	which he or she is aware have been or will be disclosed, and any of		which he or she is aware have been or will be disclosed, and any of
	which he or she become aware will be disclosed, in accordance with		which he or she become aware will be disclosed, in accordance with
	RFC 3668.		RFC 3668.
	skipping to change at page 1, line 37		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 September 13, 2005.		This Internet-Draft will expire on October 2, 2005.
	Copyright Notice		Copyright Notice
	Copyright (C) The Internet Society (2005).		Copyright (C) The Internet Society (2005).
	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 . . . . . . . . . . . . . . . . . . . . . . . . 3
	1.1 Editorial Notes . . . . . . . . . . . . . . . . . . . . . 4		1.1 Examples . . . . . . . . . . . . . . . . . . . . . . . . . 3
	1.2 Example . . . . . . . . . . . . . . . . . . . . . . . . . 5		1.2 Notational Conventions . . . . . . . . . . . . . . . . . . 5
	1.3 Notational Conventions . . . . . . . . . . . . . . . . . . 5		2. Atom Documents . . . . . . . . . . . . . . . . . . . . . . . 6
	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 The "type" Attribute . . . . . . . . . . . . . . . . . 8
	3.1.1 "type" Attribute . . . . . . . . . . . . . . . . . . . 9
	3.2 Person Constructs . . . . . . . . . . . . . . . . . . . . 11		3.2 Person Constructs . . . . . . . . . . . . . . . . . . . . 11
	3.2.1 The "atom:name" Element . . . . . . . . . . . . . . . 11		3.2.1 The "atom:name" Element . . . . . . . . . . . . . . . 11
	3.2.2 The "atom:uri" Element . . . . . . . . . . . . . . . . 11		3.2.2 The "atom:uri" Element . . . . . . . . . . . . . . . . 11
	3.2.3 The "atom:email" Element . . . . . . . . . . . . . . . 11		3.2.3 The "atom:email" Element . . . . . . . . . . . . . . . 11
	3.3 Date Constructs . . . . . . . . . . . . . . . . . . . . . 11		3.3 Date Constructs . . . . . . . . . . . . . . . . . . . . . 12
	4. Atom Element Definitions . . . . . . . . . . . . . . . . . . 13		4. Atom Element Definitions . . . . . . . . . . . . . . . . . . 13
	4.1 Container Elements . . . . . . . . . . . . . . . . . . . . 13		4.1 Container Elements . . . . . . . . . . . . . . . . . . . . 13
	4.1.1 The "atom:feed" Element . . . . . . . . . . . . . . . 13		4.1.1 The "atom:feed" Element . . . . . . . . . . . . . . . 13
	4.1.2 The "atom:entry" Element . . . . . . . . . . . . . . . 14		4.1.2 The "atom:entry" Element . . . . . . . . . . . . . . . 15
	4.1.3 The "atom:content" Element . . . . . . . . . . . . . . 16		4.1.3 The "atom:content" Element . . . . . . . . . . . . . . 17
	4.2 Metadata Elements . . . . . . . . . . . . . . . . . . . . 19		4.2 Metadata Elements . . . . . . . . . . . . . . . . . . . . 20
	4.2.1 The "atom:author" Element . . . . . . . . . . . . . . 19		4.2.1 The "atom:author" Element . . . . . . . . . . . . . . 20
	4.2.2 The "atom:category" Element . . . . . . . . . . . . . 20		4.2.2 The "atom:category" Element . . . . . . . . . . . . . 20
	4.2.3 The "atom:contributor" Element . . . . . . . . . . . . 20		4.2.3 The "atom:contributor" Element . . . . . . . . . . . . 20
	4.2.4 The "atom:copyright Element . . . . . . . . . . . . . 20		4.2.4 The "atom:copyright" Element . . . . . . . . . . . . . 21
	4.2.5 The "atom:generator" Element . . . . . . . . . . . . . 21		4.2.5 The "atom:generator" Element . . . . . . . . . . . . . 21
	4.2.6 The "atom:icon" Element . . . . . . . . . . . . . . . 21		4.2.6 The "atom:icon" Element . . . . . . . . . . . . . . . 21
	4.2.7 The "atom:id" Element . . . . . . . . . . . . . . . . 21		4.2.7 The "atom:id" Element . . . . . . . . . . . . . . . . 22
	4.2.8 The "atom:image" Element . . . . . . . . . . . . . . . 23		4.2.8 The "atom:image" Element . . . . . . . . . . . . . . . 23
	4.2.9 The "atom:link" Element . . . . . . . . . . . . . . . 23		4.2.9 The "atom:link" Element . . . . . . . . . . . . . . . 24
	4.2.10 The "atom:published" Element . . . . . . . . . . . . 26		4.2.10 The "atom:published" Element . . . . . . . . . . . . 26
	4.2.11 The "atom:source-feed" Element . . . . . . . . . . . 26		4.2.11 The "atom:source" Element . . . . . . . . . . . . . 26
	4.2.12 The "atom:subtitle" Element . . . . . . . . . . . . 26		4.2.12 The "atom:subtitle" Element . . . . . . . . . . . . 27
	4.2.13 The "atom:summary" Element . . . . . . . . . . . . . 27		4.2.13 The "atom:summary" Element . . . . . . . . . . . . . 27
	4.2.14 The "atom:title" Element . . . . . . . . . . . . . . 27		4.2.14 The "atom:title" Element . . . . . . . . . . . . . . 27
	4.2.15 The "atom:updated" Element . . . . . . . . . . . . . 27		4.2.15 The "atom:updated" Element . . . . . . . . . . . . . 27
	5. Securing Atom Documents . . . . . . . . . . . . . . . . . . 28		5. Securing Atom Documents . . . . . . . . . . . . . . . . . . 29
	5.1 Digital Signatures . . . . . . . . . . . . . . . . . . . . 28		6. Extending Atom . . . . . . . . . . . . . . . . . . . . . . . 30
	5.2 Encryption . . . . . . . . . . . . . . . . . . . . . . . . 28		7. IANA Considerations . . . . . . . . . . . . . . . . . . . . 32
	6. Extending Atom . . . . . . . . . . . . . . . . . . . . . . . 29		8. Security Considerations . . . . . . . . . . . . . . . . . . 34
	6.1 Extensions From Non-Atom Vocabularies . . . . . . . . . . 29		9. References . . . . . . . . . . . . . . . . . . . . . . . . . 35
	6.2 Extensions To the Atom Vocabulary . . . . . . . . . . . . 29		9.1 Normative References . . . . . . . . . . . . . . . . . . . 35
	6.3 Software Processing of Foreign Markup . . . . . . . . . . 29		9.2 Informative References . . . . . . . . . . . . . . . . . . 36
	6.4 Extension Elements . . . . . . . . . . . . . . . . . . . . 29		Authors' Addresses . . . . . . . . . . . . . . . . . . . . . 37
	6.4.1 Simple Extension Elements . . . . . . . . . . . . . . 30		A. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 38
	6.4.2 Structured Extension Elements . . . . . . . . . . . . 30		B. Collected RELAX NG Compact Schema . . . . . . . . . . . . . 39
	7. IANA Considerations . . . . . . . . . . . . . . . . . . . . 31		C. Change Log . . . . . . . . . . . . . . . . . . . . . . . . . 47
	7.1 Registry of Link Relations . . . . . . . . . . . . . . . . 31		Intellectual Property and Copyright Statements . . . . . . . 50
	8. Security Considerations . . . . . . . . . . . . . . . . . . 33
	8.1 HTML and XHTML Content . . . . . . . . . . . . . . . . . . 33
	8.2 URIs . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
	8.3 IRIs . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
	8.4 Encryption and Signing . . . . . . . . . . . . . . . . . . 33
	9. References . . . . . . . . . . . . . . . . . . . . . . . . . 34
	9.1 Normative References . . . . . . . . . . . . . . . . . . . 34
	9.2 Informative References . . . . . . . . . . . . . . . . . . 35
	Authors' Addresses . . . . . . . . . . . . . . . . . . . . . 36
	A. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 37
	B. Collected RELAX NG Compact Schema . . . . . . . . . . . . . 38
	C. Change Log . . . . . . . . . . . . . . . . . . . . . . . . . 45
	Intellectual Property and Copyright Statements . . . . . . . 48
	1. Introduction		1. Introduction
	Atom is an XML-based document format that describes lists of related		Atom is an XML-based document format that describes lists of related
	information known as "feeds". Feeds are composed of a number of		information known as "feeds". Feeds are composed of a number of
	items, known as "entries", each with an extensible set of attached		items, known as "entries", each with an extensible set of 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.
	1.1 Editorial Notes		1.1 Examples
	The Atom format is a work-in-progress, and this draft is both
	incomplete and likely to change rapidly. As a result, THE FORMAT
	DESCRIBED BY THIS DRAFT SHOULD NOT BE DEPLOYED, either in production
	systems or in any non-experimental fashion on the Internet.
	Discussion of this draft happens in two fora;
	The mailing list <http://www.imc.org/atom-syntax/index.html>
	The Atom Wiki Web site
	<http://www.intertwingly.net/wiki/pie/FrontPage>
	Active development takes place on the mailing list, while the Wiki is
	used for issue tracking and new proposals.
	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		<feed xmlns="http://purl.org/atom/ns#draft-ietf-atompub-format-07">
	xmlns="http://purl.org/atom/ns#draft-ietf-atompub-format-06">
	<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>
	<entry>		<entry>
	<title>Atom-Powered Robots Run Amok</title>		<title>Atom-Powered Robots Run Amok</title>
	<link href="http://example.org/2003/12/13/atom03"/>		<link href="http://example.org/2003/12/13/atom03"/>
	<id>urn:uuid:1225c695-cfb8-4ebb-aaaa-80da344efa6a</id>		<id>urn:uuid:1225c695-cfb8-4ebb-aaaa-80da344efa6a</id>
	<updated>2003-12-13T18:30:02Z</updated>		<updated>2003-12-13T18:30:02Z</updated>
			<content>Some text.</content>
	</entry>		</entry>
	</feed>
	[[anchor4: Ask yourself: is the example atom:entry valid?]]		</feed>
			A more extensive, single-entry Atom Feed Document:
	1.3 Notational Conventions		<?xml version="1.0" encoding="utf-8"?>
			<feed xmlns="http://purl.org/atom/ns#draft-ietf-atompub-format-07">
			<title type="text">dive into mark</title>
			<subtitle type="html">
			A &lt;em&gt;lot&lt;/em&gt; of effort
			went into making this effortless
			</subtitle>
			<updated>2005-04-02T12:29:29Z</updated>
			<id>tag:example.org,2003:3</id>
			<link rel="alternate" type="text/html"
			hreflang="en" href="http://example.org/"/>
			<copyright>Copyright (c) 2003, Mark Pilgrim</copyright>
			<generator uri="http://www.example.com/" version="1.0">
			Example Toolkit
			</generator>
			<entry>
			<title>Atom draft-07 snapshot</title>
			<link rel="alternate" type="text/html"
			href="http://example.org/2005/04/02/atom"/>
			<link rel="enclosure" type="audio/mpeg" length="1337"
			href="http://example.org/audio/ph34r_my_podcast.mp3"/>
			<id>tag:example.org,2003:3.2397</id>
			<updated>2005-04-02T12:29:29Z</updated>
			<published>2003-12-13T08:29:29-04:00</published>
			<author>
			<name>Mark Pilgrim</name>
			<uri>http://example.org/</uri>
			<email>f8dy@example.com</email>
			</author>
			<contributor>
			<name>Sam Ruby</name>
			<uri>http://intertwingly.net/blog/</uri>
			</contributor>
			<contributor>
			<name>Joe Gregorio</name>
			<uri>http://bitworking.org/</uri>
			</contributor>
			<content type="xhtml" xml:lang="en"
			xml:base="http://diveintomark.org/">
			<div xmlns="http://www.w3.org/1999/xhtml">
			<p><i>[Update: The Atom draft-07 snapshot is out.]</i></p>
			</div>
			</content>
			</entry>
			</feed>
	This specification describes conformance in terms of two kinds of		1.2 Notational Conventions
	artefacts; Atom Feed Documents and Atom Entry documents.
	Additionally, it places some requirements on Atom Processors.
	The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",		This specification describes conformance in terms of two artifacts;
	"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this		Atom Feed Documents and Atom Entry documents. Additionally, it
	document are to be interpreted as described in BCP 14, [RFC2119], as		places some requirements on Atom Processors.
	scoped to those conformance targets.
	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 names. It uses the following		to uniquely identify XML element names. It uses the following
	namespace prefixes for the indicated namespace URIs;		namespace prefix for the indicated namespace URI;
	"atom": http://purl.org/atom/ns#draft-ietf-atompub-format-06		"atom": http://purl.org/atom/ns#draft-ietf-atompub-format-07
	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-20040204]. However, this specification uses a		[W3C.REC-xml-infoset-20040204]. 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		Some sections of this specification are illustrated with fragments of
	a non-normative RELAX NG Compact schema [RELAX-NG]. However, the		a non-normative RELAX NG Compact schema [RELAX-NG]. However, the
	text of this specification provides the definition of conformance. A		text of this specification provides the definition of conformance. A
	collected schema appears in an informative appendix.		collected schema appears in Appendix B.
			Some sections of this specification are illustrated with Augmented
			Backus-Naur Form (ABNF), a format used to represent permissible
			strings in a protocol or language, as defined in [RFC2234].
			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], as
			scoped to those conformance targets.
	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 root is the atom:feed element.		with it. Its root is the atom:feed element.
	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 root is the atom:entry element.		the context of an Atom feed. Its root is the atom:entry element.
	namespace
	atom ="http://purl.org/atom/ns#draft-ietf-atompub-format-06"
			namespace atom =
			"http://purl.org/atom/ns#draft-ietf-atompub-format-07"
	start = atomFeed | atomEntry		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.
	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.
	Items and Processing Instruction Information Items SHOULD be ignored
	in the normal processing of an Atom Document.
	Any element in an Atom Document MAY have an xml:base attribute. XML		Any element defined by this specification MAY have an xml:base
	Base [W3C.REC-xmlbase-20010627] processing MUST be applied to any		attribute. XML Base [W3C.REC-xmlbase-20010627] processing MUST be
	relative reference [RFC3987] present in an Atom Document. This		applied to any relative reference [RFC3987] present in an Atom
	includes such elements and attributes as specified by Atom itself, as		Document. This includes such elements and attributes as specified by
	well as those specified by extensions to Atom.		Atom itself, as well as those specified by extensions to Atom.
	Any element in an Atom Document MAY have an xml:lang attribute, whose		Any element defined by this specification MAY have an xml:lang
	content indicates the natural language for the element and its		attribute, whose content indicates the natural language for the
	children. The language context is only significant for elements and		element and its children. The language context is only significant
	attributes declared to be "language-sensitive" by this specification.		for elements and attributes declared to be "language-sensitive" by
	Requirements regarding the content and interpretation of xml:lang are		this specification. Requirements regarding the content and
	specified in XML 1.0 [W3C.REC-xml-20040204], Section 2.12.		interpretation of xml:lang are specified in XML 1.0
			[W3C.REC-xml-20040204], Section 2.12.
	atomCommonAttributes =		atomCommonAttributes =
	attribute xml:base { atomUri }?,		attribute xml:base { atomUri }?,
	attribute xml:lang { atomLanguageTag }?		attribute xml:lang { atomLanguageTag }?
	Atom allows the use of IRIs [RFC3987], rather than only URIs		Atom allows the use of IRIs [RFC3987], as well as URIs [RFC3986].
	[RFC3986]. For resolution, IRIs can easily be converted to URIs.		For resolution, IRIs can easily be converted to URIs. When comparing
	When comparing IRIs serving as Identity Constructs, they MUST NOT be		IRIs serving as atom:id values, they MUST NOT be converted to URIs.
	converted to URIs. Please note that by definition, every URI is an		By definition, every URI is an IRI, so any URI can be used where an
	IRI, so any URI can be used where an IRI is needed.		IRI is needed.
	[[anchor7: discussion of white space]]
	Atom is an extensible format. See the section titled 'Extending		Atom is an extensible format. See the section titled 'Extending
	Atom' later in this document for a full description of how Atom		Atom' later in this document for a full description of how Atom
	Documents can be extended.		Documents can be extended.
	Atom Processors MAY keep state (e.g., metadata in atom:feed, entries)		Atom Processors MAY keep state (e.g., metadata in atom:feed, entries)
	sourced from Atom Feed Documents and combine them with other Atom		sourced from Atom Feed Documents and combine them with other Atom
	Feed Documents, in order to facilitate a contiguous view of the		Feed Documents, in order to facilitate a contiguous view of the
	contents of a feed. The manner in which Atom Feed Documents are		contents of a feed. The manner in which Atom Feed Documents are
	combined in order to reconstruct a feed (e.g., updating entries and		combined in order to reconstruct a feed (e.g., updating entries and
	metadata, dealing with missing entries) is out of the scope of this		metadata, dealing with missing entries) is out of the scope of this
	specification, but may be defined by an extension to Atom.		specification, but may be defined by an extension to Atom.
	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 those 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 small		A Text construct contains human-readable text, usually in small
	quantities. Except for the "type" attribute, the content of Text		quantities. The content of Text constructs is language-sensitive.
	constructs is language-sensitive.
	atomPlainTextConstruct =		atomPlainTextConstruct =
	atomCommonAttributes,		atomCommonAttributes,
	attribute type { "text" | "html" }?,		attribute type { "text" | "html" }?,
	text		text
	atomXHTMLTextConstruct =		atomXHTMLTextConstruct =
	atomCommonAttributes,		atomCommonAttributes,
	attribute type { "xhtml" },		attribute type { "xhtml" },
	(text|anyElement)*		xhtmlDiv
	atomTextConstruct = atomPlainTextConstruct | atomXHTMLTextConstruct		atomTextConstruct = atomPlainTextConstruct | atomXHTMLTextConstruct
	3.1.1 "type" Attribute		3.1.1 The "type" Attribute
	Text constructs MAY have a "type" attribute. [[anchor11: Some feel		Text constructs MAY have a "type" attribute. When present, the value
	type attributes with different allowable values in different elements		MUST be one of "text", "html" or "xhtml". If the "type" attribute is
	is confusing.]]. When present, the value MUST be one of "text",		not provided, Atom Processors MUST behave as though it were present
	"html" or "xhtml". If the "type" attribute is not provided, Atom		with a value of "text".
	Processors MUST behave as though it were present with a 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.
			3.1.1.1 Text
			Example atom:title with text content:
			...
			<title type="text">
			Less: &lt;
			</title>
			...
	If the value is "text", the content of the Text construct MUST NOT		If the value is "text", the content of the Text construct 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, Atom Processors MAY display it		humans in a readable fashion. Thus, Atom Processors MAY display it
	using normal text rendering techniques such as proportional fonts,		using normal text rendering techniques such as proportional fonts,
	white-space collapsing, and justification.		white-space collapsing, and justification.
			3.1.1.2 HTML
			Example atom:title with HTML content:
			...
			<title type="html">
			Less: &lt;em> &amp;lt; &lt;/em>
			</title>
			...
	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
	as HTML [W3C.REC-html401-19991224]. Any markup within MUST be		as HTML [W3C.REC-html401-19991224]. Any markup within MUST be
	escaped; for example, "<br>" as "&lt;br>". HTML markup within SHOULD		escaped; for example, "<br>" as "&lt;br>". HTML markup within SHOULD
	be such that it could validly appear directly within an HTML <DIV>		be such that it could validly appear directly within an HTML <DIV>
	element, after unescaping. Atom Processors that display such content		element, after unescaping. Atom Processors that display such content
	MAY use markup to aid in its display.		MAY use that markup to aid in its display.
	[[anchor12: example atom entry w/ escaped markup]]		3.1.1.3 XHTML
			Example atom:title with XHTML content:
			...
			<title type="xhtml" xmlns:xhtml="http://www.w3.org/1999/xhtml">
			<xhtml:div>
			Less: <xhtml:em> &lt; </xhtml:em>
			</xhtml:div>
			</title>
			...
	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
	MUST be a single XHTML div element [W3C.REC-xhtml-basic-20001219].		MUST be a single XHTML div element [W3C.REC-xhtml-basic-20001219].
	The XHTML div MUST contain XHTML text and markup that could validly		The XHTML div MUST contain XHTML text and markup that could validly
	appear within an XHTML div element. The XHTML div element itself		appear within an XHTML div element. The XHTML div element itself
	MUST NOT be considered part of the content. Atom Processors which		MUST NOT be considered part of the content. Atom Processors which
	display the content MAY use the markup to aid in displaying it.		display the content MAY use the markup to aid in displaying it.
	Escaped markup is interpreted as a text representation of markup, and		Escaped characters, such as "&" and ">", represent those characters,
	MUST NOT be interpreted as markup itself.		not markup.
	Example:		Examples of valid XHTML content:
	...		...
	<summary type="xhtml">		<summary type="xhtml">
	<div xmlns="http://www.w3.org/1999/xhtml">		<div xmlns="http://www.w3.org/1999/xhtml">
	This is <b>XHTML</b> content.		This is <b>XHTML</b> content.
	</div>		</div>
	</summary>		</summary>
	...		...
	<summary type="xhtml">		<summary type="xhtml">
	<xhtml:div xmlns:xhtml="http://www.w3.org/1999/xhtml">		<xhtml:div xmlns:xhtml="http://www.w3.org/1999/xhtml">
	skipping to change at page 11, line 10		skipping to change at page 11, line 10
	This is <xh:b>XHTML</xh:b> content.		This is <xh:b>XHTML</xh:b> content.
	</xh:div>		</xh:div>
	</summary>		</summary>
	...		...
	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 (hereafter, 'person').		corporation, or similar entity (hereafter, 'person').
	Person constructs MAY be extended by namespace-qualified element
	children.
	This specification assigns no significance to the order of appearance
	of the child elements in a Person construct.
	atomPersonConstruct =		atomPersonConstruct =
	atomCommonAttributes,		atomCommonAttributes,
	(element atom:name { text } &		(element atom:name { text }
	element atom:uri { atomUri }? &		& element atom:uri { atomUri }?
	element atom:email { atomEmailAddress }?)		& element atom:email { atomEmailAddress }?
			& extensionElement*)
			This specification assigns no significance to the order of appearance
			of the child elements in a Person construct. Person constructs allow
			extension Metadata Elements (see Section 6.4).
	3.2.1 The "atom:name" Element		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. The content of atom:name is language sensitive. Person		the person. The content of atom:name is language-sensitive. Person
	constructs MUST contain exactly one "atom:name" element.		constructs MUST contain exactly one "atom:name" element.
	3.2.2 The "atom:uri" Element		3.2.2 The "atom:uri" Element
	The "atom:uri" element's content conveys an IRI associated with the		The "atom:uri" element's content conveys an IRI 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 an IRI reference [RFC3987].		construct MUST be an IRI reference [RFC3987].
	xml:base [W3C.REC-xmlbase-20010627] processing MUST be applied to the
	atom:uri element's content.
	3.2.3 The "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 person. Person constructs MAY contain an		associated with the person. 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 conform to the addr-spec BNF rule in [RFC2822].		MUST conform to the addr-spec BNF rule in [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]. I.e., the content of this element		extended date-time form ABNF rule in [RFC3339]. In addition, an
	matches this regular expression:		uppercase "T" character MUST be used to separate date and time, and
			an uppercase "Z" character MUST be present in the absence of a
	[0-9]{8}T[0-9]{2}:[0-9]{2}:[0-9]{2}(\.[0-9]+)		numeric time zone offset.
	?(Z|[\+\-][0-9]{2}:[0-9]{2})
	As a result, the date values conform to the following specifications:
	[RFC3339], [W3C.REC-xmlschema-2-20041028],
	[W3C.NOTE-datetime-19980827], and [ISO.8601.1988].
	atomDateConstruct =		atomDateConstruct =
	atomCommonAttributes,		atomCommonAttributes,
	xsd:dateTime		xsd:dateTime
			Such date values happen to be compatible with the following
			specifications: [ISO.8601.1988], [W3C.NOTE-datetime-19980827], and
			[W3C.REC-xmlschema-2-20041028].
			Date values SHOULD be as accurate as possible. For example, it would
			be generally inappropriate for a publishing system to apply the same
			timestamp to several entries which were published during the course
			of a single day.
	4. Atom Element Definitions		4. Atom Element Definitions
	4.1 Container Elements		4.1 Container Elements
	4.1.1 The "atom:feed" Element		4.1.1 The "atom:feed" Element
	[[anchor21: Substantially changed from format-05, review carefully.]]
	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 element children consist of one or		associated with the feed. Its element children consist of metadata
	more metadata elements followed by zero or more atom:entry child		elements followed by zero or more atom:entry child elements.
	elements.
	This specification assigns no significance to the order of atom:entry
	elements within the feed.
	atomFeed =		atomFeed =
	element atom:feed {		element atom:feed {
	atomCommonAttributes,		atomCommonAttributes,
	(atomAuthor?		(atomAuthor?
	& atomCategory*		& atomCategory*
	& atomContributor*		& atomContributor*
	& atomCopyright?		& atomCopyright?
	& atomGenerator?		& atomGenerator?
	& atomIcon?		& atomIcon?
	& atomId?		& atomId?
	& atomImage?		& atomImage?
	& atomLink+		& atomLink+
	& atomSubtitle?		& atomSubtitle?
	& atomTitle		& atomTitle
	& atomUpdated		& atomUpdated
	& anyElement* ),		& extensionElement*),
	atomEntry*		atomEntry*
	}		}
			This specification assigns no significance to the order of atom:entry
			elements within the feed.
	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):
	o atom:feed elements MUST contain exactly one atom:author element,		o atom:feed elements MUST contain exactly one atom:author element,
	UNLESS all of the atom:feed element's child atom:entry elements		UNLESS all of the atom:feed element's child atom:entry elements
	contain an atom:author element. atom:feed elements MUST NOT		contain an atom:author element. atom:feed elements MUST NOT
	contain more than one atom:author element. [[anchor22:		contain more than one atom:author element.
	inheritance]]
	o atom:feed elements MAY contain any number of atom:category		o atom:feed elements MAY contain any number of atom:category
	elements.		elements.
	o atom:feed elements MAY contain any number of atom:contributor