draft-ietf-atompub-format-03.txt		draft-ietf-atompub-format-04.txt
	Network Working Group M. Nottingham, Ed.		Network Working Group M. Nottingham, Ed.
	Internet-Draft		Internet-Draft
	Expires: April 20, 2005 R. Sayre, Ed.		Expires: July 11, 2005 R. Sayre, Ed.
	Boswijck Memex Consulting		Boswijck Memex Consulting
	October 20, 2004		January 10, 2005
	The Atom Syndication Format		The Atom Syndication Format
	draft-ietf-atompub-format-03		draft-ietf-atompub-format-04
	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 April 20, 2005.		This Internet-Draft will expire on July 11, 2005.
	Copyright Notice		Copyright Notice
	Copyright (C) The Internet Society (2004). 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 . . . . . . . . . . . . . . . . . . . 8
	3.1 Text Constructs . . . . . . . . . . . . . . . . . . . . . 8		3.1 Text Constructs . . . . . . . . . . . . . . . . . . . . . 8
	3.1.1 "type" Attribute . . . . . . . . . . . . . . . . . . . 8		3.1.1 "type" Attribute . . . . . . . . . . . . . . . . . . . 8
	3.2 Person Constructs . . . . . . . . . . . . . . . . . . . . 8		3.2 Person Constructs . . . . . . . . . . . . . . . . . . . . 9
	3.2.1 "atom:name" Element . . . . . . . . . . . . . . . . . 9		3.2.1 "atom:name" Element . . . . . . . . . . . . . . . . . 9
	3.2.2 "atom:uri" Element . . . . . . . . . . . . . . . . . . 9		3.2.2 "atom:uri" Element . . . . . . . . . . . . . . . . . . 9
	3.2.3 "atom:email" Element . . . . . . . . . . . . . . . . . 9		3.2.3 "atom:email" Element . . . . . . . . . . . . . . . . . 9
	3.3 Date Constructs . . . . . . . . . . . . . . . . . . . . . 9		3.3 Date Constructs . . . . . . . . . . . . . . . . . . . . . 9
	3.4 Service Constructs . . . . . . . . . . . . . . . . . . . . 9		3.4 Service Constructs . . . . . . . . . . . . . . . . . . . . 9
	3.4.1 "href" Attribute . . . . . . . . . . . . . . . . . . . 9		3.4.1 "href" Attribute . . . . . . . . . . . . . . . . . . . 10
	3.5 Link Constructs . . . . . . . . . . . . . . . . . . . . . 10		3.5 Link Constructs . . . . . . . . . . . . . . . . . . . . . 10
	3.5.1 "rel" Attribute . . . . . . . . . . . . . . . . . . . 10		3.5.1 "rel" Attribute . . . . . . . . . . . . . . . . . . . 10
	3.5.2 "type" Attribute . . . . . . . . . . . . . . . . . . . 10		3.5.2 "type" Attribute . . . . . . . . . . . . . . . . . . . 11
	3.5.3 "href" Attribute . . . . . . . . . . . . . . . . . . . 10		3.5.3 "href" Attribute . . . . . . . . . . . . . . . . . . . 11
	3.5.4 "hreflang" Attribute . . . . . . . . . . . . . . . . . 10		3.5.4 "hreflang" Attribute . . . . . . . . . . . . . . . . . 11
	3.5.5 "title" Attribute . . . . . . . . . . . . . . . . . . 11		3.5.5 "title" Attribute . . . . . . . . . . . . . . . . . . 11
	3.6 Identity Constructs . . . . . . . . . . . . . . . . . . . 11		3.5.6 "length" Attribute . . . . . . . . . . . . . . . . . . 11
	3.6.1 Dereferencing Identity Constructs . . . . . . . . . . 11		3.6 Identity Constructs . . . . . . . . . . . . . . . . . . . 12
			3.6.1 Dereferencing Identity Constructs . . . . . . . . . . 12
	3.6.2 Comparing Identity Constructs . . . . . . . . . . . . 12		3.6.2 Comparing Identity Constructs . . . . . . . . . . . . 12
	4. The "atom:feed" Element . . . . . . . . . . . . . . . . . . 13		3.7 The Category Construct . . . . . . . . . . . . . . . . . . 13
	4.1 "version" Attribute . . . . . . . . . . . . . . . . . . . 13		3.7.1 The "term" Attribute . . . . . . . . . . . . . . . . . 13
	4.2 The "atom:head" Element . . . . . . . . . . . . . . . . . 13		3.7.2 The "scheme" Attribute . . . . . . . . . . . . . . . . 13
	4.2.1 "atom:title" Element . . . . . . . . . . . . . . . . . 13		3.7.3 The "label" attribute . . . . . . . . . . . . . . . . 13
	4.2.2 "atom:link" Element . . . . . . . . . . . . . . . . . 13		4. The "atom:feed" Element . . . . . . . . . . . . . . . . . . 14
	4.2.3 "atom:introspection" Element . . . . . . . . . . . . . 14		4.1 "version" Attribute . . . . . . . . . . . . . . . . . . . 14
	4.2.4 "atom:post" Element . . . . . . . . . . . . . . . . . 14		4.2 The "atom:head" Element . . . . . . . . . . . . . . . . . 14
	4.2.5 "atom:author" Element . . . . . . . . . . . . . . . . 14		4.2.1 "atom:title" Element . . . . . . . . . . . . . . . . . 14
	4.2.6 "atom:contributor" Element . . . . . . . . . . . . . . 14		4.2.2 "atom:link" Element . . . . . . . . . . . . . . . . . 14
	4.2.7 "atom:tagline" Element . . . . . . . . . . . . . . . . 14		4.2.3 "atom:category" Element . . . . . . . . . . . . . . . 15
	4.2.8 "atom:id" Element . . . . . . . . . . . . . . . . . . 14		4.2.4 "atom:introspection" Element . . . . . . . . . . . . . 15
	4.2.9 "atom:generator" Element . . . . . . . . . . . . . . . 15		4.2.5 "atom:post" Element . . . . . . . . . . . . . . . . . 15
	4.2.10 "atom:copyright" Element . . . . . . . . . . . . . . 15		4.2.6 "atom:author" Element . . . . . . . . . . . . . . . . 15
	4.2.11 "atom:info" Element . . . . . . . . . . . . . . . . 15		4.2.7 "atom:contributor" Element . . . . . . . . . . . . . . 15
	4.2.12 "atom:updated" Element . . . . . . . . . . . . . . . 16		4.2.8 "atom:tagline" Element . . . . . . . . . . . . . . . . 15
	5. The "atom:entry" Element . . . . . . . . . . . . . . . . . . 17		4.2.9 "atom:id" Element . . . . . . . . . . . . . . . . . . 16
	5.1 "atom:title" Element . . . . . . . . . . . . . . . . . . . 17		4.2.10 "atom:generator" Element . . . . . . . . . . . . . . 16
	5.2 "atom:link" Element . . . . . . . . . . . . . . . . . . . 17		4.2.11 "atom:copyright" Element . . . . . . . . . . . . . . 16
	5.3 "atom:edit" Element . . . . . . . . . . . . . . . . . . . 17		4.2.12 "atom:info" Element . . . . . . . . . . . . . . . . 16
	5.4 "atom:author" Element . . . . . . . . . . . . . . . . . . 18		4.2.13 "atom:updated" Element . . . . . . . . . . . . . . . 16
	5.5 "atom:contributor" Element . . . . . . . . . . . . . . . . 18		5. The "atom:entry" Element . . . . . . . . . . . . . . . . . . 18
	5.6 "atom:id" Element . . . . . . . . . . . . . . . . . . . . 18		5.1 "atom:title" Element . . . . . . . . . . . . . . . . . . . 18
	5.7 "atom:updated" Element . . . . . . . . . . . . . . . . . . 18		5.2 "atom:link" Element . . . . . . . . . . . . . . . . . . . 18
	5.8 "atom:published" Element . . . . . . . . . . . . . . . . . 18		5.3 "atom:category" Element . . . . . . . . . . . . . . . . . 18
	5.9 "atom:summary" Element . . . . . . . . . . . . . . . . . . 19		5.4 "atom:edit" Element . . . . . . . . . . . . . . . . . . . 19
	5.10 "atom:content" Element . . . . . . . . . . . . . . . . . 19		5.5 "atom:author" Element . . . . . . . . . . . . . . . . . . 19
	5.10.1 "type" attribute . . . . . . . . . . . . . . . . . . 19		5.6 "atom:contributor" Element . . . . . . . . . . . . . . . . 19
	5.10.2 "src" attribute . . . . . . . . . . . . . . . . . . 19		5.7 "atom:host" Element . . . . . . . . . . . . . . . . . . . 19
	5.10.3 Processing Model . . . . . . . . . . . . . . . . . . 20		5.8 "atom:id" Element . . . . . . . . . . . . . . . . . . . . 19
	5.11 "atom:copyright" Element . . . . . . . . . . . . . . . . 21		5.9 "atom:updated" Element . . . . . . . . . . . . . . . . . . 19
	5.12 "atom:origin" Element . . . . . . . . . . . . . . . . . 21		5.10 "atom:published" Element . . . . . . . . . . . . . . . . 20
	6. Managing Feed State . . . . . . . . . . . . . . . . . . . . 22		5.11 "atom:summary" Element . . . . . . . . . . . . . . . . . 20
	7. Securing Atom Documents . . . . . . . . . . . . . . . . . . 23		5.12 "atom:content" Element . . . . . . . . . . . . . . . . . 20
	7.1 Digital Signatures . . . . . . . . . . . . . . . . . . . . 23		5.12.1 "type" attribute . . . . . . . . . . . . . . . . . . 20
	7.2 Encryption . . . . . . . . . . . . . . . . . . . . . . . . 23		5.12.2 "src" attribute . . . . . . . . . . . . . . . . . . 21
	8. Embedding Atom in Other Formats . . . . . . . . . . . . . . 24		5.12.3 Processing Model . . . . . . . . . . . . . . . . . . 21
	9. Extending Atom . . . . . . . . . . . . . . . . . . . . . . . 25		5.13 "atom:copyright" Element . . . . . . . . . . . . . . . . 22
	10. IANA Considerations . . . . . . . . . . . . . . . . . . . . 26		5.14 "atom:head" Element . . . . . . . . . . . . . . . . . . 22
	11. Security Considerations . . . . . . . . . . . . . . . . . . 27		6. Managing Feed State . . . . . . . . . . . . . . . . . . . . 23
	12. Normative References . . . . . . . . . . . . . . . . . . . . 27		7. Securing Atom Documents . . . . . . . . . . . . . . . . . . 24
	Authors' Addresses . . . . . . . . . . . . . . . . . . . . . 28		7.1 Digital Signatures . . . . . . . . . . . . . . . . . . . . 24
	A. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 29		7.2 Encryption . . . . . . . . . . . . . . . . . . . . . . . . 24
	B. Revision History . . . . . . . . . . . . . . . . . . . . . . 30		8. Embedding Atom in Other Formats . . . . . . . . . . . . . . 25
	Intellectual Property and Copyright Statements . . . . . . . 32		9. Extending Atom . . . . . . . . . . . . . . . . . . . . . . . 26
			10. IANA Considerations . . . . . . . . . . . . . . . . . . . . 27
			10.1 Registry of Link Relations . . . . . . . . . . . . . . . 27
			11. Security Considerations . . . . . . . . . . . . . . . . . . 29
			12. References . . . . . . . . . . . . . . . . . . . . . . . . . 30
			12.1 Normative References . . . . . . . . . . . . . . . . . . . 30
			12.2 Informative References . . . . . . . . . . . . . . . . . . 31
			Authors' Addresses . . . . . . . . . . . . . . . . . . . . . 32
			A. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 33
			B. Revision History . . . . . . . . . . . . . . . . . . . . . . 34
			Intellectual Property and Copyright Statements . . . . . . . 36
	1. Introduction		1. Introduction
	Atom is an XML-based document format intended to allow lists of		Atom is an XML-based document format intended to allow lists of
	related information, known as "feeds", to be synchronised between		related information, known as "feeds". Feeds are composed of a
	publishers and consumers. Feeds are composed of a number of items,		number of items, known as "entries", each with an extensible set of
	known as "entries", each with an extensible set of attached metadata.		attached metadata. For example, each entry has a title.
	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 9		skipping to change at page 5, line 9
	used for issue tracking and new proposals.		used for issue tracking and new proposals.
	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-03: do not deploy"		<feed version="draft-ietf-atompub-format-04
	xmlns="http://purl.org/atom/ns#draft-ietf-atompub-format-03">		: do not deploy"
			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 43		skipping to change at page 5, line 45
	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-03		"atom": http://purl.org/atom/ns#draft-ietf-atompub-format-04
	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.
	skipping to change at page 7, line 32		skipping to change at page 7, line 32
	[[ Validity? ]]		[[ 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 URI reference present in an Atom document. This includes		relative reference [RFC2396bis] present in an Atom Document. This
	such elements and attributes as specified by Atom itself, as well as		includes such elements and attributes as specified by Atom itself, 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 default natural language of the element's
	content. Requirements regarding the content and interpretation of		content. Requirements regarding the content and interpretation of
	xml:lang are specified in XML 1.0 [W3C.REC-xml-20040204] Section		xml:lang are specified in XML 1.0 [W3C.REC-xml-20040204] Section
	2.12.		2.12.
	[[ discussion of URI escaping and i18n ]]		[[ 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
	skipping to change at page 8, line 38		skipping to change at page 8, line 38
	the "type" attribute.		the "type" attribute.
	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, software MAY display it using		humans in a readable fashion. Thus, software MAY display it using
	normal text rendering techniques such as proportional fonts,		normal text rendering techniques such as proportional fonts,
	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 encoded; 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.
	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.		markup to aid in displaying it. Escaped markup is interpreted as a
			text representation of markup, and MUST NOT be interpreted as markup
			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 atom:entry.		of the child elements of a Person construct.
	3.2.1 "atom:name" Element		3.2.1 "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 "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 [RFC2396].		construct MUST be a URI reference [RFC2396bis].
	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 "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].
	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.		entry or feed. The type of service is identified by the element
			name.
	A Service construct has the following attribute:		A Service construct has the following attribute:
	3.4.1 "href" Attribute		3.4.1 "href" Attribute
	The "href" attribute contains the a URI pointing to the endpoint of		The "href" attribute contains the a URI pointing to the endpoint of
	the service named by the name attribute. atom:service elements MUST		the service named by the name attribute. atom:service elements MUST
	have a "href" attribute, whose value MUST be a URI.		have a "href" attribute, whose value MUST be a URI reference
			[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 Link Constructs
	A Link construct is an empty element that describes a connection from		A Link construct is an empty element that describes a connection from
	an Atom document to another Web resource.		an Atom Document to another Web resource.
	3.5.1 "rel" Attribute		3.5.1 "rel" Attribute
	The "rel" attribute indicates the type of relationship that the link		Link constructs MAY have an optional "rel" attribute that indicates
	represents. Link constructs MAY have a rel attribute, whose value		the link relation type. If the "rel" attribute is not present, the
	MUST be a string, and MUST be one of the following values:		link construct MUST be interpreted as if the link relation type is
	"alternate", "related".		"alternate".
	If the "rel" attribute is not present, the link element MUST be		rel_attribute = segment-nz-nc / URI
	interpreted as if the value "alternate" had been supplied.
			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		3.5.2 "type" Attribute
	The "type" attribute indicates an advisory media type; it MAY be used		Link constructs MAY have a type attribute, whose value MUST conform
	as a hint to determine the type of the representation which should be		to the syntax of a MIME media type [RFC2045].
	returned when the URI in the href attribute is dereferenced. Note
	that the type attribute does not override the actual media type
	returned with the representation.
	Link constructs MAY have a type attribute, whose value MUST be a		The type attribute's value is an advisory media type; it MAY be used
	registered media type [RFC2045].		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		3.5.3 "href" Attribute
	The "href" attribute contains the link's URI. Link constructs MUST		The "href" attribute contains the link's URI. Link constructs MUST
	have a href attribute, whose value MUST be a URI [RFC2396].		have a href attribute, whose value MUST be a URI reference
			[RFC2396bis].
	xml:base [W3C.REC-xmlbase-20010627] processing MUST be applied to the		xml:base [W3C.REC-xmlbase-20010627] processing MUST be applied to the
	href attribute's content.		href attribute's content.
	3.5.4 "hreflang" Attribute		3.5.4 "hreflang" Attribute
	The "hreflang" attribute's content describes the language of the		The "hreflang" attribute's content describes the language of the
	resource pointed to by the href attribute. When used together with		resource pointed to by the href attribute. When used together with
	the rel="alternate", it implies a translated version of the entry.		the rel="alternate", it implies a translated version of the entry.
	Link constructs MAY have an hreflang attribute, whose value MUST be a		Link constructs MAY have an hreflang attribute, whose value MUST be a
	language tag [RFC3066].		language tag [RFC3066].
	3.5.5 "title" Attribute		3.5.5 "title" Attribute
	The "title" attribute conveys human-readable information about the		The "title" attribute conveys human-readable information about the
	link. Link constructs MAY have a title attribute.		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		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 an absolute URI [RFC2396].		Its content MUST be a URI, as defined by [RFC2396bis]. Note that the
			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		3.6.1 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
	skipping to change at page 11, line 48		skipping to change at page 12, line 44
	o Only perform percent-encoding where it is essential.		o Only perform percent-encoding where it is essential.
	o Use uppercase A-through-F characters when percent-encoding.		o Use uppercase A-through-F characters when percent-encoding.
	o Prevent dot-segments appearing in paths.		o Prevent dot-segments appearing in paths.
	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		3.6.2 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
	skipping to change at page 13, line 5		skipping to change at page 13, line 19
	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
			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. 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		4.1 "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-03: do not deploy".		"draft-ietf-atompub-format-04 : 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.
	skipping to change at page 14, line 12		skipping to change at page 15, line 12
	with a rel attribute value of "alternate" that has the same type		with a rel attribute value of "alternate" that has the same type
	attribute value.		attribute value.
	If a feed's atom:link element with type="alternate" resolves to an		If a feed's atom:link element with type="alternate" resolves to an
	HTML document, then that document SHOULD have a autodiscovery link		HTML document, then that document SHOULD have a autodiscovery link
	element [Atom-autodiscovery] that reflects back to the feed.		element [Atom-autodiscovery] that reflects back to the feed.
	atom:head elements MAY contain additional atom:link elements beyond		atom:head elements MAY contain additional atom:link elements beyond
	those described above.		those described above.
	4.2.3 "atom:introspection" Element		4.2.3 "atom:category" Element
			A Category Construct identifying a category with which the feed is
			associated. atom:head elements MAY contain any number of
			atom:category elements.
			4.2.4 "atom:introspection" Element
	The "atom:introspection" element is a Service construct that conveys		The "atom:introspection" element is a Service construct that conveys
	the URI of an introspection file associated with the feed. atom:head		the URI of an introspection file associated with the feed. atom:head
	elements MUST NOT contain more than one atom:introspection element.		elements MUST NOT contain more than one atom:introspection element.
	4.2.4 "atom:post" Element		4.2.5 "atom:post" Element
	The "atom:post" element is a Service construct that conveys the URI		The "atom:post" element is a Service construct that conveys the URI
	used to add