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diff --git a/result/valid/xhtml1.xhtml b/result/valid/xhtml1.xhtml deleted file mode 100644 index 907209b..0000000 --- a/result/valid/xhtml1.xhtml +++ /dev/null @@ -1,1453 +0,0 @@ -<?xml version="1.0"?> -<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "dtds/xhtml1-strict.dtd"> -<?xml-stylesheet href="W3C-PR.css" type="text/css"?> -<html xmlns="http://www.w3.org/1999/xhtml" lang="en" xml:lang="en"> -<head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /> -<title>XHTML 1.0: The Extensible HyperText Markup -Language</title> -<link rel="stylesheet" href="W3C-PR.css" type="text/css" /> -<style type="text/css"> -span.term { font-style: italic; color: rgb(0, 0, 192) } -code { - color: green; - font-family: monospace; - font-weight: bold; -} - -code.greenmono { - color: green; - font-family: monospace; - font-weight: bold; -} -.good { - border: solid green; - border-width: 2px; - color: green; - font-weight: bold; - margin-right: 5%; - margin-left: 0; -} -.bad { - border: solid red; - border-width: 2px; - margin-left: 0; - margin-right: 5%; - color: rgb(192, 101, 101); -} - -img { - color: white; - border: none; -} - -div.navbar { text-align: center; } -div.contents { - background-color: rgb(204,204,255); - padding: 0.5em; - border: none; - margin-right: 5%; -} -.tocline { list-style: none; } -table.exceptions { background-color: rgb(255,255,153); } -</style> -</head> -<body> -<div class="navbar"> - <a href="#toc">table of contents</a> - <hr /> -</div> -<div class="head"><p><a href="http://www.w3.org/"><img class="head" src="w3c_home.gif" alt="W3C" /></a></p> - -<h1 class="head"><a name="title" id="title">XHTML</a><sup>™</sup> 1.0: -The Extensible HyperText Markup Language</h1> - -<h2>A Reformulation of HTML 4.0 in XML 1.0</h2> - -<h3>W3C Proposed Recommendation 10 December 1999</h3> - -<dl> -<dt>This version:</dt> - -<dd><a href="http://www.w3.org/TR/1999/PR-xhtml1-19991210"> -http://www.w3.org/TR/1999/PR-xhtml1-19991210</a> <br /> -(<a href="xhtml1.ps">Postscript version</a>, -<a href="xhtml1.pdf">PDF version</a>, -<a href="xhtml1.zip">ZIP archive</a>, or -<a href="xhtml1.tgz">Gzip'd TAR archive</a>) -</dd> - -<dt>Latest version:</dt> - -<dd><a href="http://www.w3.org/TR/xhtml1"> -http://www.w3.org/TR/xhtml1</a></dd> - -<dt>Previous versions:</dt> - -<dd><a href="http://www.w3.org/TR/1999/WD-xhtml1-19991124"> -http://www.w3.org/TR/1999/WD-xhtml1-19991124</a></dd> -<dd><a href="http://www.w3.org/TR/1999/PR-xhtml1-19990824"> -http://www.w3.org/TR/1999/PR-xhtml1-19990824</a></dd> - -<dt>Authors:</dt> - -<dd>See <a href="#acks">acknowledgements</a>.</dd> -</dl> - -<p class="copyright"><a href="http://www.w3.org/Consortium/Legal/ipr-notice#Copyright"> -Copyright</a> © 1999 <a href="http://www.w3.org/">W3C</a><sup>®</sup> -(<a href="http://www.lcs.mit.edu/">MIT</a>, <a href="http://www.inria.fr/">INRIA</a>, <a href="http://www.keio.ac.jp/">Keio</a>), All Rights Reserved. <abbr title="World Wide Web Consortium">W3C</abbr> <a href="http://www.w3.org/Consortium/Legal/ipr-notice#Legal_Disclaimer"> -liability</a>, <a href="http://www.w3.org/Consortium/Legal/ipr-notice#W3C_Trademarks"> -trademark</a>, <a href="http://www.w3.org/Consortium/Legal/copyright-documents">document -use</a> and <a href="http://www.w3.org/Consortium/Legal/copyright-software">software -licensing</a> rules apply.</p> -<hr /> -</div> - -<h2 class="notoc">Abstract</h2> - -<p>This specification defines <abbr title="Extensible Hypertext Markup Language">XHTML</abbr> 1.0, a reformulation of HTML -4.0 as an XML 1.0 application, and three <abbr title="Document Type Definition">DTDs</abbr> corresponding to -the ones defined by HTML 4.0. The semantics of the elements and -their attributes are defined in the W3C Recommendation for HTML -4.0. These semantics provide the foundation for future -extensibility of XHTML. Compatibility with existing HTML user -agents is possible by following a small set of guidelines.</p> - -<h2>Status of this document</h2> - -<p><em>This section describes the status of this document at the time -of its publication. Other documents may supersede this document. The -latest status of this document series is maintained at the W3C.</em></p> - -<p>This specification is a Proposed Recommendation of the HTML Working Group. It is -a revision of the Proposed Recommendation dated <a href="http://www.w3.org/TR/1999/PR-xhtml1-19990824/">24 August -1999</a> incorporating changes as a result of comments from the Proposed -Recommendation review, and -comments and further deliberations of the W3C HTML Working Group. A -<a href="xhtml1-diff-19991210.html">diff-marked version</a> from the previous -proposed recommendation is available for comparison purposes.</p> - -<p>On 10 December 1999, this document enters a -<a href="http://www.w3.org/Consortium/Process/#RecsPR"> -Proposed Recommendation</a> review period. From that date until 8 January -2000, -W3C Advisory Committee representatives are encouraged -to review this specification and return comments in their completed -ballots to w3c-html-review@w3.org. Please send any comments of a -confidential nature in separate email to w3t-html@w3.org, which is -visible to the Team only.</p> - -<p>No sooner than 14 days after the end of the review period, the -Director will announce the document's disposition: it may become a W3C -Recommendation (possibly with minor changes), it may revert to Working -Draft status, or it may be dropped as a W3C work item.</p> - -<p>Publication as a Proposed Recommendation does not imply endorsement -by the W3C membership. This is still a draft document and may be -updated, replaced or obsoleted by other documents at any time. It is -inappropriate to cite W3C Proposed Recommendation as other than "work -in progress."</p> - -<p>This document has been produced as part of the <a href="http://www.w3.org/MarkUp/">W3C HTML Activity</a>. The goals of -the <a href="http://www.w3.org/MarkUp/Group/">HTML Working -Group</a> <i>(<a href="http://cgi.w3.org/MemberAccess/">members -only</a>)</i> are discussed in the <a href="http://www.w3.org/MarkUp/Group/HTMLcharter">HTML Working Group -charter</a> <i>(<a href="http://cgi.w3.org/MemberAccess/">members -only</a>)</i>.</p> - -<p>A list of current W3C Recommendations and other technical documents -can be found at <a href="http://www.w3.org/TR">http://www.w3.org/TR</a>.</p> - -<p>Public discussion on <abbr title="HyperText Markup Language">HTML</abbr> features takes place on the mailing list <a href="mailto:www-html@w3.org"> www-html@w3.org</a> (<a href="http://lists.w3.org/Archives/Public/www-html/">archive</a>). The W3C -staff contact for work on HTML is <a href="mailto:dsr@w3.org">Dave -Raggett</a>.</p> - -<p>Please report errors in this document to <a href="mailto:www-html-editor@w3.org">www-html-editor@w3.org</a>.</p> - -<p>The list of known errors in this specification is available at <a href="http://www.w3.org/1999/12/PR-xhtml1-19991210-errata">http://www.w3.org/1999/12/PR-xhtml1-19991210-errata</a>.</p> - -<h2 class="notoc"><a id="toc" name="toc">Contents</a></h2> - -<div class="contents"> -<ul class="toc"> -<li class="tocline">1. <a href="#xhtml">What is XHTML?</a> - -<ul class="toc"> -<li class="tocline">1.1 <a href="#html4">What is HTML 4.0?</a></li> - -<li class="tocline">1.2 <a href="#xml">What is XML?</a></li> - -<li class="tocline">1.3 <a href="#why">Why the need for XHTML?</a></li> -</ul> -</li> - -<li class="tocline">2. <a href="#defs">Definitions</a> - -<ul class="toc"> -<li class="tocline">2.1 <a href="#terms">Terminology</a></li> - -<li class="tocline">2.2 <a href="#general">General Terms</a></li> -</ul> -</li> - -<li class="tocline">3. <a href="#normative">Normative Definition of XHTML 1.0</a> - - -<ul class="toc"> -<li class="tocline">3.1 <a href="#docconf">Document Conformance</a></li> - -<li class="tocline">3.2 <a href="#uaconf">User Agent Conformance</a></li> -</ul> -</li> - -<li class="tocline">4. <a href="#diffs">Differences with HTML 4.0</a> - -</li> - -<li class="tocline">5. <a href="#issues">Compatibility Issues</a> - -<ul class="toc"> -<li class="tocline">5.1 <a href="#media">Internet Media Types</a></li> -</ul> -</li> - -<li class="tocline">6. <a href="#future">Future Directions</a> - -<ul class="toc"> -<li class="tocline">6.1 <a href="#mods">Modularizing HTML</a></li> - -<li class="tocline">6.2 <a href="#extensions">Subsets and Extensibility</a></li> - -<li class="tocline">6.3 <a href="#profiles">Document Profiles</a></li> -</ul> -</li> - -<li class="tocline"><a href="#dtds">Appendix A. DTDs</a></li> - -<li class="tocline"><a href="#prohibitions">Appendix B. Element -Prohibitions</a></li> - -<li class="tocline"><a href="#guidelines">Appendix C. HTML Compatibility Guidelines</a></li> - -<li class="tocline"><a href="#acks">Appendix D. Acknowledgements</a></li> - -<li class="tocline"><a href="#refs">Appendix E. References</a></li> -</ul> -</div> - -<!--OddPage--> -<h1><a name="xhtml" id="xhtml">1. What is XHTML?</a></h1> - -<p>XHTML is a family of current and future document types and modules that -reproduce, subset, and extend HTML 4.0 <a href="#ref-html4">[HTML]</a>. XHTML family document types are <abbr title="Extensible Markup Language">XML</abbr> based, -and ultimately are designed to work in conjunction with XML-based user agents. -The details of this family and its evolution are -discussed in more detail in the section on <a href="#future">Future -Directions</a>. </p> - -<p>XHTML 1.0 (this specification) is the first document type in the XHTML -family. It is a reformulation of the three HTML 4.0 document types as -applications of XML 1.0 <a href="#ref-xml"> [XML]</a>. It is intended -to be used as a language for content that is both XML-conforming and, if some -simple <a href="#guidelines">guidelines</a> are followed, -operates in HTML 4.0 conforming user agents. Developers who migrate -their content to XHTML 1.0 will realize the following benefits:</p> - -<ul> -<li>XHTML documents are XML conforming. As such, they are readily viewed, -edited, and validated with standard XML tools.</li> -<li>XHTML documents can be written to -to operate as well or better than they did before in existing -HTML 4.0-conforming user agents as well as in new, XHTML 1.0 conforming user -agents.</li> -<li>XHTML documents can utilize applications (e.g. scripts and applets) that rely -upon either the HTML Document Object Model or the XML Document Object Model <a href="#ref-dom">[DOM]</a>.</li> -<li>As the XHTML family evolves, documents conforming to XHTML 1.0 will be more -likely to interoperate within and among various XHTML environments.</li> -</ul> - -<p>The XHTML family is the next step in the evolution of the Internet. By -migrating to XHTML today, content developers can enter the XML world with all -of its attendant benefits, while still remaining confident in their -content's backward and future compatibility.</p> - -<h2><a name="html4" id="html4">1.1 What is HTML 4.0?</a></h2> - -<p>HTML 4.0 <a href="#ref-html4">[HTML]</a> is an <abbr title="Standard Generalized Markup Language">SGML</abbr> (Standard -Generalized Markup Language) application conforming to -International Standard <abbr title="Organization for International Standardization">ISO</abbr> 8879, and is widely regarded as the -standard publishing language of the World Wide Web.</p> - -<p>SGML is a language for describing markup languages, -particularly those used in electronic document exchange, document -management, and document publishing. HTML is an example of a -language defined in SGML.</p> - -<p>SGML has been around since the middle 1980's and has remained -quite stable. Much of this stability stems from the fact that the -language is both feature-rich and flexible. This flexibility, -however, comes at a price, and that price is a level of -complexity that has inhibited its adoption in a diversity of -environments, including the World Wide Web.</p> - -<p>HTML, as originally conceived, was to be a language for the -exchange of scientific and other technical documents, suitable -for use by non-document specialists. HTML addressed the problem -of SGML complexity by specifying a small set of structural and -semantic tags suitable for authoring relatively simple documents. -In addition to simplifying the document structure, HTML added -support for hypertext. Multimedia capabilities were added -later.</p> - -<p>In a remarkably short space of time, HTML became wildly -popular and rapidly outgrew its original purpose. Since HTML's -inception, there has been rapid invention of new elements for use -within HTML (as a standard) and for adapting HTML to vertical, -highly specialized, markets. This plethora of new elements has -led to compatibility problems for documents across different -platforms.</p> - -<p>As the heterogeneity of both software and platforms rapidly -proliferate, it is clear that the suitability of 'classic' HTML -4.0 for use on these platforms is somewhat limited.</p> - -<h2><a name="xml" id="xml">1.2 What is XML?</a></h2> - -<p>XML<sup>™</sup> is the shorthand for Extensible Markup -Language, and is an acronym of Extensible Markup Language <a href="#ref-xml">[XML]</a>.</p> - -<p>XML was conceived as a means of regaining the power and -flexibility of SGML without most of its complexity. Although a -restricted form of SGML, XML nonetheless preserves most of SGML's -power and richness, and yet still retains all of SGML's commonly -used features.</p> - -<p>While retaining these beneficial features, XML removes many of -the more complex features of SGML that make the authoring and -design of suitable software both difficult and costly.</p> - -<h2><a name="why" id="why">1.3 Why the need for XHTML?</a></h2> - -<p>The benefits of migrating to XHTML 1.0 are described above. Some of the -benefits of migrating to XHTML in general are:</p> - -<ul> -<li>Document developers and user agent designers are constantly -discovering new ways to express their ideas through new markup. In XML, it is -relatively easy to introduce new elements or additional element -attributes. The XHTML family is designed to accommodate these extensions -through XHTML modules and techniques for developing new XHTML-conforming -modules (described in the forthcoming XHTML Modularization specification). -These modules will permit the combination of existing and -new feature sets when developing content and when designing new user -agents.</li> - -<li>Alternate ways of accessing the Internet are constantly being -introduced. Some estimates indicate that by the year 2002, 75% of -Internet document viewing will be carried out on these alternate -platforms. The XHTML family is designed with general user agent -interoperability in mind. Through a new user agent and document profiling -mechanism, servers, proxies, and user agents will be able to perform -best effort content transformation. Ultimately, it will be possible to -develop XHTML-conforming content that is usable by any XHTML-conforming -user agent.</li> - -</ul> -<!--OddPage--> -<h1><a name="defs" id="defs">2. Definitions</a></h1> - -<h2><a name="terms" id="terms">2.1 Terminology</a></h2> - -<p>The following terms are used in this specification. These -terms extend the definitions in <a href="#ref-rfc2119"> -[RFC2119]</a> in ways based upon similar definitions in ISO/<abbr title="International Electro-technical Commission">IEC</abbr> -9945-1:1990 <a href="#ref-posix">[POSIX.1]</a>:</p> - -<dl> -<dt>Implementation-defined</dt> - -<dd>A value or behavior is implementation-defined when it is left -to the implementation to define [and document] the corresponding -requirements for correct document construction.</dd> - -<dt>May</dt> - -<dd>With respect to implementations, the word "may" is to be -interpreted as an optional feature that is not required in this -specification but can be provided. With respect to <a href="#docconf">Document Conformance</a>, the word "may" means that -the optional feature must not be used. The term "optional" has -the same definition as "may".</dd> - -<dt>Must</dt> - -<dd>In this specification, the word "must" is to be interpreted -as a mandatory requirement on the implementation or on Strictly -Conforming XHTML Documents, depending upon the context. The term -"shall" has the same definition as "must".</dd> - -<dt>Reserved</dt> - -<dd>A value or behavior is unspecified, but it is not allowed to -be used by Conforming Documents nor to be supported by a -Conforming User Agents.</dd> - -<dt>Should</dt> - -<dd>With respect to implementations, the word "should" is to be -interpreted as an implementation recommendation, but not a -requirement. With respect to documents, the word "should" is to -be interpreted as recommended programming practice for documents -and a requirement for Strictly Conforming XHTML Documents.</dd> - -<dt>Supported</dt> - -<dd>Certain facilities in this specification are optional. If a -facility is supported, it behaves as specified by this -specification.</dd> - -<dt>Unspecified</dt> - -<dd>When a value or behavior is unspecified, the specification -defines no portability requirements for a facility on an -implementation even when faced with a document that uses the -facility. A document that requires specific behavior in such an -instance, rather than tolerating any behavior when using that -facility, is not a Strictly Conforming XHTML Document.</dd> -</dl> - -<h2><a name="general" id="general">2.2 General Terms</a></h2> - -<dl> -<dt>Attribute</dt> - -<dd>An attribute is a parameter to an element declared in the -DTD. An attribute's type and value range, including a possible -default value, are defined in the DTD.</dd> - -<dt>DTD</dt> - -<dd>A DTD, or document type definition, is a collection of XML -declarations that, as a collection, defines the legal structure, -<span class="term">elements</span>, and <span class="term"> -attributes</span> that are available for use in a document that -complies to the DTD.</dd> - -<dt>Document</dt> - -<dd>A document is a stream of data that, after being combined -with any other streams it references, is structured such that it -holds information contained within <span class="term"> -elements</span> that are organized as defined in the associated -<span class="term">DTD</span>. See <a href="#docconf">Document -Conformance</a> for more information.</dd> - -<dt>Element</dt> - -<dd>An element is a document structuring unit declared in the -<span class="term">DTD</span>. The element's content model is -defined in the <span class="term">DTD</span>, and additional -semantics may be defined in the prose description of the -element.</dd> - -<dt><a name="facilities" id="facilities">Facilities</a></dt> - -<dd>Functionality includes <span class="term">elements</span>, -<span class="term">attributes</span>, and the semantics -associated with those <span class="term">elements</span> and -<span class="term">attributes</span>. An implementation -supporting that functionality is said to provide the necessary -facilities.</dd> - -<dt>Implementation</dt> - -<dd>An implementation is a system that provides collection of -<span class="term">facilities</span> and services that supports -this specification. See <a href="#uaconf">User Agent -Conformance</a> for more information.</dd> - -<dt>Parsing</dt> - -<dd>Parsing is the act whereby a <span class="term"> -document</span> is scanned, and the information contained within -the <span class="term">document</span> is filtered into the -context of the <span class="term">elements</span> in which the -information is structured.</dd> - -<dt>Rendering</dt> - -<dd>Rendering is the act whereby the information in a <span class="term">document</span> is presented. This presentation is -done in the form most appropriate to the environment (e.g. -aurally, visually, in print).</dd> - -<dt>User Agent</dt> - -<dd>A user agent is an <span class="term">implementation</span> -that retrieves and processes XHTML documents. See <a href="#uaconf">User Agent Conformance</a> for more information.</dd> - -<dt>Validation</dt> - -<dd>Validation is a process whereby <span class="term"> -documents</span> are verified against the associated <span class="term">DTD</span>, ensuring that the structure, use of <span class="term">elements</span>, and use of <span class="term"> -attributes</span> are consistent with the definitions in the -<span class="term">DTD</span>.</dd> - -<dt><a name="wellformed" id="wellformed">Well-formed</a></dt> - -<dd>A <span class="term">document</span> is well-formed when it -is structured according to the rules defined in <a href="http://www.w3.org/TR/REC-xml#sec-well-formed">Section 2.1</a> of -the XML 1.0 Recommendation <a href="#ref-xml">[XML]</a>. -Basically, this definition states that elements, delimited by -their start and end tags, are nested properly within one -another.</dd> -</dl> - -<!--OddPage--> -<h1><a name="normative" id="normative">3. Normative Definition of -XHTML 1.0</a></h1> - -<h2><a name="docconf" id="docconf">3.1 Document -Conformance</a></h2> - -<p>This version of XHTML provides a definition of strictly -conforming XHTML documents, which are restricted to tags and -attributes from the XHTML namespace. See <a href="#well-formed">Section 3.1.2</a> for information on using XHTML -with other namespaces, for instance, to include metadata -expressed in <abbr title="Resource Description Format">RDF</abbr> within XHTML documents.</p> - -<h3><a name="strict" id="strict">3.1.1 Strictly Conforming -Documents</a></h3> - -<p>A Strictly Conforming XHTML Document is a document that -requires only the facilities described as mandatory in this -specification. Such a document must meet all of the following -criteria:</p> - -<ol> -<li> -<p>It must validate against one of the three DTDs found in <a href="#dtds">Appendix A</a>.</p> -</li> - -<li> -<p>The root element of the document must be <code> -<html></code>.</p> -</li> - -<li> -<p>The root element of the document must designate the XHTML -namespace using the <code>xmlns</code> attribute <a href="#ref-xmlns">[XMLNAMES]</a>. The namespace for XHTML is -defined to be -<code>http://www.w3.org/1999/xhtml</code>.</p> -</li> - -<li> -<p>There must be a DOCTYPE declaration in the document prior to -the root element. The public identifier included in -the DOCTYPE declaration must reference one of the three DTDs -found in <a href="#dtds">Appendix A</a> using the respective -Formal Public Identifier. The system identifier may be changed to reflect -local system conventions.</p> - -<pre> -<!DOCTYPE html - PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" - "http://www.w3.org/TR/1999/PR-xhtml1-19991210/DTD/xhtml1-strict.dtd> - -<!DOCTYPE html - PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" - "http://www.w3.org/TR/1999/PR-xhtml1-19991210/DTD/xhtml1-transitional.dtd> - -<!DOCTYPE html - PUBLIC "-//W3C//DTD XHTML 1.0 Frameset//EN" - "http://www.w3.org/TR/1999/PR-xhtml1-19991210/DTD/xhtml1-frameset.dtd> -</pre> -</li> -</ol> - -<p>Here is an example of a minimal XHTML document.</p> - -<div class="good"> -<pre> -<?xml version="1.0" encoding="UTF-8"?> -<!DOCTYPE html - PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" - "http://www.w3.org/TR/1999/PR-xhtml1-19991210/DTD/xhtml1-strict.dtd"> -<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"> - <head> - <title>Virtual Library</title> - </head> - <body> - <p>Moved to <a href="http://vlib.org/">vlib.org</a>.</p> - </body> -</html></pre> -</div> - -<p>Note that in this example, the XML declaration is included. An XML -declaration like the one above is -not required in all XML documents. XHTML document authors are strongly encouraged to use XML declarations in all their documents. Such a declaration is required -when the character encoding of the document is other than the default UTF-8 or -UTF-16.</p> - -<h3><a name="well-formed" id="well-formed">3.1.2 Using XHTML with -other namespaces</a></h3> - -<p>The XHTML namespace may be used with other XML namespaces -as per <a href="#ref-xmlns">[XMLNAMES]</a>, although such -documents are not strictly conforming XHTML 1.0 documents as -defined above. Future work by W3C will address ways to specify -conformance for documents involving multiple namespaces.</p> - -<p>The following example shows the way in which XHTML 1.0 could -be used in conjunction with the MathML Recommendation:</p> - -<div class="good"> -<pre> -<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"> - <head> - <title>A Math Example</title> - </head> - <body> - <p>The following is MathML markup:</p> - <math xmlns="http://www.w3.org/1998/Math/MathML"> - <apply> <log/> - <logbase> - <cn> 3 </cn> - </logbase> - <ci> x </ci> - </apply> - </math> - </body> -</html> -</pre> -</div> - -<p>The following example shows the way in which XHTML 1.0 markup -could be incorporated into another XML namespace:</p> - -<div class="good"> -<pre> -<?xml version="1.0" encoding="UTF-8"?> -<!-- initially, the default namespace is "books" --> -<book xmlns='urn:loc.gov:books' - xmlns:isbn='urn:ISBN:0-395-36341-6' xml:lang="en" lang="en"> - <title>Cheaper by the Dozen</title> - <isbn:number>1568491379</isbn:number> - <notes> - <!-- make HTML the default namespace for a hypertext commentary --> - <p xmlns='http://www.w3.org/1999/xhtml'> - This is also available <a href="http://www.w3.org/">online</a>. - </p> - </notes> -</book> -</pre> -</div> - -<h2><a name="uaconf" id="uaconf">3.2 User Agent -Conformance</a></h2> - -<p>A conforming user agent must meet all of the following -criteria:</p> - -<ol> -<li>In order to be consistent with the XML 1.0 Recommendation <a href="#ref-xml">[XML]</a>, the user agent must parse and evaluate -an XHTML document for well-formedness. If the user agent claims -to be a validating user agent, it must also validate documents -against their referenced DTDs according to <a href="#ref-xml"> -[XML]</a>.</li> - -<li>When the user agent claims to support <a href="#facilities"> -facilities</a> defined within this specification or required by -this specification through normative reference, it must do so in -ways consistent with the facilities' definition.</li> - -<li>When a user agent processes an XHTML document as generic XML, -it shall only recognize attributes of type -<code>ID</code> (e.g. the <code>id</code> attribute on most XHTML elements) -as fragment identifiers.</li> - -<li>If a user agent encounters an element it does not recognize, -it must render the element's content.</li> - -<li>If a user agent encounters an attribute it does not -recognize, it must ignore the entire attribute specification -(i.e., the attribute and its value).</li> - -<li>If a user agent encounters an attribute value it doesn't -recognize, it must use the default attribute value.</li> - -<li>If it encounters an entity reference (other than one -of the predefined entities) for which the User Agent has -processed no declaration (which could happen if the declaration -is in the external subset which the User Agent hasn't read), the entity -reference should be rendered as the characters (starting -with the ampersand and ending with the semi-colon) that -make up the entity reference.</li> - -<li>When rendering content, User Agents that encounter -characters or character entity references that are recognized but not renderable should display the document in such a way that it is obvious to the user that normal rendering has not taken place.</li> - -<li> -The following characters are defined in [XML] as whitespace characters: - -<ul> -<li>Space (&#x0020;)</li> -<li>Tab (&#x0009;)</li> -<li>Carriage return (&#x000D;)</li> -<li>Line feed (&#x000A;)</li> -</ul> - -<p> -The XML processor normalizes different system's line end codes into one -single line-feed character, that is passed up to the application. The XHTML -user agent in addition, must treat the following characters as whitespace: -</p> - -<ul> -<li>Form feed (&#x000C;)</li> -<li>Zero-width space (&#x200B;)</li> -</ul> - -<p> -In elements where the 'xml:space' attribute is set to 'preserve', the user -agent must leave all whitespace characters intact (with the exception of -leading and trailing whitespace characters, which should be removed). -Otherwise, whitespace -is handled according to the following rules: -</p> - -<ul> -<li> -All whitespace surrounding block elements should be removed. -</li> -<li> -Comments are removed entirely and do not affect whitespace handling. One -whitespace character on either side of a comment is treated as two white -space characters. -</li> -<li> -Leading and trailing whitespace inside a block element must be removed. -</li> -<li>Line feed characters within a block element must be converted into a -space (except when the 'xml:space' attribute is set to 'preserve'). -</li> -<li> -A sequence of white space characters must be reduced to a single space -character (except when the 'xml:space' attribute is set to 'preserve'). -</li> -<li> -With regard to rendition, -the User Agent should render the content in a -manner appropriate to the language in which the content is written. -In languages whose primary script is Latinate, the ASCII space -character is typically used to encode both grammatical word boundaries and -typographic whitespace; in languages whose script is related to Nagari -(e.g., Sanskrit, Thai, etc.), grammatical boundaries may be encoded using -the ZW 'space' character, but will not typically be represented by -typographic whitespace in rendered output; languages using Arabiform scripts -may encode typographic whitespace using a space character, but may also use -the ZW space character to delimit 'internal' grammatical boundaries (what -look like words in Arabic to an English eye frequently encode several words, -e.g. 'kitAbuhum' = 'kitAbu-hum' = 'book them' == their book); and languages -in the Chinese script tradition typically neither encode such delimiters nor -use typographic whitespace in this way. -</li> -</ul> - -<p>Whitespace in attribute values is processed according to <a href="#ref-xml">[XML]</a>.</p> -</li> -</ol> - -<!--OddPage--> -<h1><a name="diffs" id="diffs">4. Differences with HTML -4.0</a></h1> - -<p>Due to the fact that XHTML is an XML application, certain -practices that were perfectly legal in SGML-based HTML 4.0 <a href="#ref-html4">[HTML]</a> must be changed.</p> - -<h2><a name="h-4.1" id="h-4.1">4.1 Documents must be -well-formed</a></h2> - -<p><a href="#wellformed">Well-formedness</a> is a new concept -introduced by <a href="#ref-xml">[XML]</a>. Essentially this -means that all elements must either have closing tags or be -written in a special form (as described below), and that all the -elements must nest.</p> - -<p>Although overlapping is illegal in SGML, it was widely -tolerated in existing browsers.</p> - -<div class="good"> -<p><strong><em>CORRECT: nested elements.</em></strong></p> - -<p><p>here is an emphasized -<em>paragraph</em>.</p></p> -</div> - -<div class="bad"> -<p><strong><em>INCORRECT: overlapping elements</em></strong></p> - -<p><p>here is an emphasized -<em>paragraph.</p></em></p> -</div> - -<h2><a name="h-4.2" id="h-4.2">4.2 Element and attribute -names must be in lower case</a></h2> - -<p>XHTML documents must use lower case for all HTML element and -attribute names. This difference is necessary because XML is -case-sensitive e.g. <li> and <LI> are different -tags.</p> - -<h2><a name="h-4.3" id="h-4.3">4.3 For non-empty elements, -end tags are required</a></h2> - -<p>In SGML-based HTML 4.0 certain elements were permitted to omit -the end tag; with the elements that followed implying closure. -This omission is not permitted in XML-based XHTML. All elements -other than those declared in the DTD as <code>EMPTY</code> must -have an end tag.</p> - -<div class="good"> -<p><strong><em>CORRECT: terminated elements</em></strong></p> - -<p><p>here is a paragraph.</p><p>here is -another paragraph.</p></p> -</div> - -<div class="bad"> -<p><strong><em>INCORRECT: unterminated elements</em></strong></p> - -<p><p>here is a paragraph.<p>here is another -paragraph.</p> -</div> - -<h2><a name="h-4.4" id="h-4.4">4.4 Attribute values must -always be quoted</a></h2> - -<p>All attribute values must be quoted, even those which appear -to be numeric.</p> - -<div class="good"> -<p><strong><em>CORRECT: quoted attribute values</em></strong></p> - -<p><table rows="3"></p> -</div> - -<div class="bad"> -<p><strong><em>INCORRECT: unquoted attribute values</em></strong></p> - -<p><table rows=3></p> -</div> - -<h2><a name="h-4.5" id="h-4.5">4.5 Attribute -Minimization</a></h2> - -<p>XML does not support attribute minimization. Attribute-value -pairs must be written in full. Attribute names such as <code> -compact</code> and <code>checked</code> cannot occur in elements -without their value being specified.</p> - -<div class="good"> -<p><strong><em>CORRECT: unminimized attributes</em></strong></p> - -<p><dl compact="compact"></p> -</div> - -<div class="bad"> -<p><strong><em>INCORRECT: minimized attributes</em></strong></p> - -<p><dl compact></p> -</div> - -<h2><a name="h-4.6" id="h-4.6">4.6 Empty Elements</a></h2> - -<p>Empty elements must either have an end tag or the start tag must end with <code>/></code>. For instance, -<code><br/></code> or <code><hr></hr></code>. See <a href="#guidelines">HTML Compatibility Guidelines</a> for information on ways to -ensure this is backward compatible with HTML 4.0 user agents.</p> - -<div class="good"> -<p><strong><em>CORRECT: terminated empty tags</em></strong></p> - -<p><br/><hr/></p> -</div> - -<div class="bad"> -<p><strong><em>INCORRECT: unterminated empty tags</em></strong></p> - -<p><br><hr></p> -</div> - -<h2><a name="h-4.7" id="h-4.7">4.7 Whitespace handling in -attribute values</a></h2> - -<p>In attribute values, user agents will strip leading and -trailing whitespace from attribute values and map sequences -of one or more whitespace characters (including line breaks) to -a single inter-word space (an ASCII space character for western -scripts). See <a href="http://www.w3.org/TR/REC-xml#AVNormalize"> -Section 3.3.3</a> of <a href="#ref-xml">[XML]</a>.</p> - -<h2><a name="h-4.8" id="h-4.8">4.8 Script and Style -elements</a></h2> - -<p>In XHTML, the script and style elements are declared as having -<code>#PCDATA</code> content. As a result, <code><</code> and -<code>&</code> will be treated as the start of markup, and -entities such as <code>&lt;</code> and <code>&amp;</code> -will be recognized as entity references by the XML processor to -<code><</code> and <code>&</code> respectively. Wrapping -the content of the script or style element within a <code> -CDATA</code> marked section avoids the expansion of these -entities.</p> - -<div class="good"> -<pre> -<script> - <![CDATA[ - ... unescaped script content ... - ]]> - </script> -</pre> -</div> - -<p><code>CDATA</code> sections are recognized by the XML -processor and appear as nodes in the Document Object Model, see -<a href="http://www.w3.org/TR/REC-DOM-Level-1/level-one-core.html#ID-E067D597"> -Section 1.3</a> of the DOM Level 1 Recommendation <a href="#ref-dom">[DOM]</a>.</p> - -<p>An alternative is to use external script and style -documents.</p> - -<h2><a name="h-4.9" id="h-4.9">4.9 SGML exclusions</a></h2> - -<p>SGML gives the writer of a DTD the ability to exclude specific -elements from being contained within an element. Such -prohibitions (called "exclusions") are not possible in XML.</p> - -<p>For example, the HTML 4.0 Strict DTD forbids the nesting of an -'<code>a</code>' element within another '<code>a</code>' element -to any descendant depth. It is not possible to spell out such -prohibitions in XML. Even though these prohibitions cannot be -defined in the DTD, certain elements should not be nested. A -summary of such elements and the elements that should not be -nested in them is found in the normative <a href="#prohibitions"> -Appendix B</a>.</p> - -<h2><a name="h-4.10" id="h-4.10">4.10 The elements with 'id' and 'name' -attributes</a></h2> - -<p>HTML 4.0 defined the <code>name</code> attribute for the elements -<code>a</code>, -<code>applet</code>, <code>frame</code>, -<code>iframe</code>, <code>img</code>, and <code>map</code>. -HTML 4.0 also introduced -the <code>id</code> attribute. Both of these attributes are designed to be -used as fragment identifiers.</p> -<p>In XML, fragment identifiers are of type <code>ID</code>, and -there can only be a single attribute of type <code>ID</code> per element. -Therefore, in XHTML 1.0 the <code>id</code> -attribute is defined to be of type <code>ID</code>. In order to -ensure that XHTML 1.0 documents are well-structured XML documents, XHTML 1.0 -documents MUST use the <code>id</code> attribute when defining fragment -identifiers, even on elements that historically have also had a -<code>name</code> attribute. -See the <a href="#guidelines">HTML Compatibility -Guidelines</a> for information on ensuring such anchors are backwards -compatible when serving XHTML documents as media type <code>text/html</code>. -</p> -<p>Note that in XHTML 1.0, the <code>name</code> attribute of these -elements is formally deprecated, and will be removed in a -subsequent version of XHTML.</p> - -<!--OddPage--> -<h1><a name="issues" id="issues">5. Compatibility Issues</a></h1> - -<p>Although there is no requirement for XHTML 1.0 documents to be -compatible with existing user agents, in practice this is easy to -accomplish. Guidelines for creating compatible documents can be -found in <a href="#guidelines">Appendix C</a>.</p> - -<h2><a name="media" id="media">5.1 Internet Media Type</a></h2> -<p>As of the publication of this recommendation, the general -recommended MIME labeling for XML-based applications -has yet to be resolved.</p> - -<p>However, XHTML Documents which follow the guidelines set forth -in <a href="#guidelines">Appendix C</a>, "HTML Compatibility Guidelines" may be -labeled with the Internet Media Type "text/html", as they -are compatible with most HTML browsers. This document -makes no recommendation about MIME labeling of other -XHTML documents.</p> - -<!--OddPage--> -<h1><a name="future" id="future">6. Future Directions</a></h1> - -<p>XHTML 1.0 provides the basis for a family of document types -that will extend and subset XHTML, in order to support a wide -range of new devices and applications, by defining modules and -specifying a mechanism for combining these modules. This -mechanism will enable the extension and sub-setting of XHTML 1.0 -in a uniform way through the definition of new modules.</p> - -<h2><a name="mods" id="mods">6.1 Modularizing HTML</a></h2> - -<p>As the use of XHTML moves from the traditional desktop user -agents to other platforms, it is clear that not all of the XHTML -elements will be required on all platforms. For example a hand -held device or a cell-phone may only support a subset of XHTML -elements.</p> - -<p>The process of modularization breaks XHTML up into a series of -smaller element sets. These elements can then be recombined to -meet the needs of different communities.</p> - -<p>These modules will be defined in a later W3C document.</p> - -<h2><a name="extensions" id="extensions">6.2 Subsets and -Extensibility</a></h2> - -<p>Modularization brings with it several advantages:</p> - -<ul> -<li> -<p>It provides a formal mechanism for sub-setting XHTML.</p> -</li> - -<li> -<p>It provides a formal mechanism for extending XHTML.</p> -</li> - -<li> -<p>It simplifies the transformation between document types.</p> -</li> - -<li> -<p>It promotes the reuse of modules in new document types.</p> -</li> -</ul> - -<h2><a name="profiles" id="profiles">6.3 Document -Profiles</a></h2> - -<p>A document profile specifies the syntax and semantics of a set -of documents. Conformance to a document profile provides a basis -for interoperability guarantees. The document profile specifies -the facilities required to process documents of that type, e.g. -which image formats can be used, levels of scripting, style sheet -support, and so on.</p> - -<p>For product designers this enables various groups to define -their own standard profile.</p> - -<p>For authors this will obviate the need to write several -different versions of documents for different clients.</p> - -<p>For special groups such as chemists, medical doctors, or -mathematicians this allows a special profile to be built using -standard HTML elements plus a group of elements geared to the -specialist's needs.</p> - -<!--OddPage--> -<h1><a name="appendices" id="appendices"></a> -<a name="dtds" id="dtds">Appendix A. DTDs</a></h1> - -<p><b>This appendix is normative.</b></p> - -<p>These DTDs and entity sets form a normative part of this -specification. The complete set of DTD files together with an XML -declaration and SGML Open Catalog is included in the <a href="xhtml1.zip">zip file</a> for this specification.</p> - -<h2><a name="h-A1" id="h-A1">A.1 Document Type -Definitions</a></h2> - -<p>These DTDs approximate the HTML 4.0 DTDs. It is likely that -when the DTDs are modularized, a method of DTD construction will -be employed that corresponds more closely to HTML 4.0.</p> - -<ul> -<li> -<p><a href="DTD/xhtml1-strict.dtd" type="text/plain"> -XHTML-1.0-Strict</a></p> -</li> - -<li> -<p><a href="DTD/xhtml1-transitional.dtd" type="text/plain"> -XHTML-1.0-Transitional</a></p> -</li> - -<li> -<p><a href="DTD/xhtml1-frameset.dtd" type="text/plain"> -XHTML-1.0-Frameset</a></p> -</li> -</ul> - -<h2><a name="h-A2" id="h-A2">A.2 Entity Sets</a></h2> - -<p>The XHTML entity sets are the same as for HTML 4.0, but have -been modified to be valid XML 1.0 entity declarations. Note the -entity for the Euro currency sign (<code>&euro;</code> or -<code>&#8364;</code> or <code>&#x20AC;</code>) is defined -as part of the special characters.</p> - -<ul> -<li> -<p><a href="DTD/xhtml-lat1.ent">Latin-1 characters</a></p> -</li> - -<li> -<p><a href="DTD/xhtml-special.ent">Special characters</a></p> -</li> - -<li> -<p><a href="DTD/xhtml-symbol.ent">Symbols</a></p> -</li> -</ul> - -<!--OddPage--> -<h1><a name="prohibitions" id="prohibitions">Appendix B. Element -Prohibitions</a></h1> - -<p><b>This appendix is normative.</b></p> - -<p>The following elements have prohibitions on which elements -they can contain (see <a href="#h-4.9">Section 4.9</a>). This -prohibition applies to all depths of nesting, i.e. it contains -all the descendant elements.</p> - -<dl><dt><code class="tag">a</code></dt> -<dd> -cannot contain other <code>a</code> elements.</dd> -<dt><code class="tag">pre</code></dt> -<dd>cannot contain the <code>img</code>, <code>object</code>, -<code>big</code>, <code>small</code>, <code>sub</code>, or <code> -sup</code> elements.</dd> - -<dt><code class="tag">button</code></dt> -<dd>cannot contain the <code>input</code>, <code>select</code>, -<code>textarea</code>, <code>label</code>, <code>button</code>, -<code>form</code>, <code>fieldset</code>, <code>iframe</code> or -<code>isindex</code> elements.</dd> -<dt><code class="tag">label</code></dt> -<dd>cannot contain other <code class="tag">label</code> elements.</dd> -<dt><code class="tag">form</code></dt> -<dd>cannot contain other <code>form</code> elements.</dd> -</dl> - -<!--OddPage--> -<h1><a name="guidelines" id="guidelines">Appendix C. -HTML Compatibility Guidelines</a></h1> - -<p><b>This appendix is informative.</b></p> - -<p>This appendix summarizes design guidelines for authors who -wish their XHTML documents to render on existing HTML user -agents.</p> - -<h2>C.1 Processing Instructions</h2> -<p>Be aware that processing instructions are rendered on some -user agents. However, also note that when the XML declaration is not included -in a document, the document can only use the default character encodings UTF-8 -or UTF-16.</p> - -<h2>C.2 Empty Elements</h2> -<p>Include a space before the trailing <code>/</code> and <code> -></code> of empty elements, e.g. <code class="greenmono"> -<br /></code>, <code class="greenmono"> -<hr /></code> and <code class="greenmono"><img -src="karen.jpg" alt="Karen" /></code>. Also, use the -minimized tag syntax for empty elements, e.g. <code class="greenmono"><br /></code>, as the alternative syntax <code class="greenmono"><br></br></code> allowed by XML -gives uncertain results in many existing user agents.</p> - -<h2>C.3 Element Minimization and Empty Element Content</h2> -<p>Given an empty instance of an element whose content model is -not <code>EMPTY</code> (for example, an empty title or paragraph) -do not use the minimized form (e.g. use <code class="greenmono"> -<p> </p></code> and not <code class="greenmono"> -<p /></code>).</p> - -<h2>C.4 Embedded Style Sheets and Scripts</h2> -<p>Use external style sheets if your style sheet uses <code> -<</code> or <code>&</code> or <code>]]></code> or <code>--</code>. Use -external scripts if your script uses <code><</code> or <code> -&</code> or <code>]]></code> or <code>--</code>. Note that XML parsers -are permitted to silently remove the contents of comments. Therefore, the historical -practice of "hiding" scripts and style sheets within comments to make the -documents backward compatible is likely to not work as expected in XML-based -implementations.</p> - -<h2>C.5 Line Breaks within Attribute Values</h2> -<p>Avoid line breaks and multiple whitespace characters within -attribute values. These are handled inconsistently by user -agents.</p> - -<h2>C.6 Isindex</h2> -<p>Don't include more than one <code>isindex</code> element in -the document <code>head</code>. The <code>isindex</code> element -is deprecated in favor of the <code>input</code> element.</p> - -<h2>C.7 The <code>lang</code> and <code>xml:lang</code> Attributes</h2> -<p>Use both the <code>lang</code> and <code>xml:lang</code> -attributes when specifying the language of an element. The value -of the <code>xml:lang</code> attribute takes precedence.</p> - -<h2>C.8 Fragment Identifiers</h2> -<p>In XML, <abbr title="Uniform Resource Identifiers">URIs</abbr> [<a href="#ref-rfc2396">RFC2396</a>] that end with fragment identifiers of the form -<code>"#foo"</code> do not refer to elements with an attribute -<code>name="foo"</code>; rather, they refer to elements with an -attribute defined to be of type <code>ID</code>, e.g., the <code> -id</code> attribute in HTML 4.0. Many existing HTML clients don't -support the use of <code>ID</code>-type attributes in this way, -so identical values may be supplied for both of these attributes to ensure -maximum forward and backward compatibility (e.g., <code class="greenmono"><a id="foo" name="foo">...</a></code>).</p> - -<p>Further, since the set of -legal values for attributes of type <code>ID</code> is much smaller than -for those of type <code>CDATA</code>, the type of the <code>name</code> -attribute has been changed to <code>NMTOKEN</code>. This attribute is -constrained such that it can only have the same values as type -<code>ID</code>, or as the <code>Name</code> production in XML 1.0 Section -2.5, production 5. Unfortunately, this constraint cannot be expressed in the -XHTML 1.0 DTDs. Because of this change, care must be taken when -converting existing HTML documents. The values of these attributes -must be unique within the document, valid, and any references to these -fragment identifiers (both -internal and external) must be updated should the values be changed during -conversion.</p> -<p>Finally, note that XHTML 1.0 has deprecated the -<code>name</code> attribute of the <code>a</code>, <code>applet</code>, <code>frame</code>, <code>iframe</code>, <code>img</code>, and <code>map</code> -elements, and it will be -removed from XHTML in subsequent versions.</p> - -<h2>C.9 Character Encoding</h2> -<p>To specify a character encoding in the document, use both the -encoding attribute specification on the xml declaration (e.g. -<code class="greenmono"><?xml version="1.0" -encoding="EUC-JP"?></code>) and a meta http-equiv statement -(e.g. <code class="greenmono"><meta http-equiv="Content-type" -content='text/html; charset="EUC-JP"' /></code>). The -value of the encoding attribute of the xml processing instruction -takes precedence.</p> - -<h2>C.10 Boolean Attributes</h2> -<p>Some HTML user agents are unable to interpret boolean -attributes when these appear in their full (non-minimized) form, -as required by XML 1.0. Note this problem doesn't effect user -agents compliant with HTML 4.0. The following attributes are -involved: <code>compact</code>, <code>nowrap</code>, <code> -ismap</code>, <code>declare</code>, <code>noshade</code>, <code> -checked</code>, <code>disabled</code>, <code>readonly</code>, -<code>multiple</code>, <code>selected</code>, <code> -noresize</code>, <code>defer</code>.</p> - -<h2>C.11 Document Object Model and XHTML</h2> -<p> -The Document Object Model level 1 Recommendation [<a href="#ref-dom">DOM</a>] -defines document object model interfaces for XML and HTML 4.0. The HTML 4.0 -document object model specifies that HTML element and attribute names are -returned in upper-case. The XML document object model specifies that -element and attribute names are returned in the case they are specified. In -XHTML 1.0, elements and attributes are specified in lower-case. This apparent difference can be -addressed in two ways: -</p> -<ol> -<li>Applications that access XHTML documents served as Internet media type -<code>text/html</code> -via the <abbr title="Document Object Model">DOM</abbr> can use the HTML DOM, -and can rely upon element and attribute names being returned in -upper-case from those interfaces.</li> -<li>Applications that access XHTML documents served as Internet media types -<code>text/xml</code> or <code>application/xml</code> -can also use the XML DOM. Elements and attributes will be returned in lower-case. -Also, some XHTML elements may or may -not appear -in the object tree because they are optional in the content model -(e.g. the <code>tbody</code> element within -<code>table</code>). This occurs because in HTML 4.0 some elements were -permitted to be minimized such that their start and end tags are both omitted -(an SGML feature). -This is not possible in XML. Rather than require document authors to insert -extraneous elements, XHTML has made the elements optional. -Applications need to adapt to this -accordingly.</li> -</ol> - -<h2>C.12 Using Ampersands in Attribute Values</h2> -<p> -When an attribute value contains an ampersand, it must be expressed as a character -entity reference -(e.g. "<code>&amp;</code>"). For example, when the -<code>href</code> attribute -of the <code>a</code> element refers to a -CGI script that takes parameters, it must be expressed as -<code>http://my.site.dom/cgi-bin/myscript.pl?class=guest&amp;name=user</code> -rather than as -<code>http://my.site.dom/cgi-bin/myscript.pl?class=guest&name=user</code>. -</p> - -<h2>C.13 Cascading Style Sheets (CSS) and XHTML</h2> - -<p>The Cascading Style Sheets level 2 Recommendation [<a href="#ref-css2">CSS2</a>] defines style -properties which are applied to the parse tree of the HTML or XML -document. Differences in parsing will produce different visual or -aural results, depending on the selectors used. The following hints -will reduce this effect for documents which are served without -modification as both media types:</p> - -<ol> -<li> -CSS style sheets for XHTML should use lower case element and -attribute names.</li> - - -<li>In tables, the tbody element will be inferred by the parser of an -HTML user agent, but not by the parser of an XML user agent. Therefore -you should always explicitely add a tbody element if it is referred to -in a CSS selector.</li> - -<li>Within the XHTML name space, user agents are expected to -recognize the "id" attribute as an attribute of type ID. -Therefore, style sheets should be able to continue using the -shorthand "#" selector syntax even if the user agent does not read -the DTD.</li> - -<li>Within the XHTML name space, user agents are expected to -recognize the "class" attribute. Therefore, style sheets should be -able to continue using the shorthand "." selector syntax.</li> - -<li> -CSS defines different conformance rules for HTML and XML documents; -be aware that the HTML rules apply to XHTML documents delivered as -HTML and the XML rules apply to XHTML documents delivered as XML.</li> -</ol> -<!--OddPage--> -<h1><a name="acks" id="acks">Appendix D. -Acknowledgements</a></h1> - -<p><b>This appendix is informative.</b></p> - -<p>This specification was written with the participation of the -members of the W3C HTML working group:</p> - -<dl> -<dd>Steven Pemberton, CWI (HTML Working Group Chair)<br /> -Murray Altheim, Sun Microsystems<br /> -Daniel Austin, CNET: The Computer Network<br /> -Frank Boumphrey, HTML Writers Guild<br /> -John Burger, Mitre<br /> -Andrew W. Donoho, IBM<br /> -Sam Dooley, IBM<br /> -Klaus Hofrichter, GMD<br /> -Philipp Hoschka, W3C<br /> -Masayasu Ishikawa, W3C<br /> -Warner ten Kate, Philips Electronics<br /> -Peter King, Phone.com<br /> -Paula Klante, JetForm<br /> -Shin'ichi Matsui, W3C/Panasonic<br /> -Shane McCarron, Applied Testing and Technology (The Open Group through August -1999)<br /> -Ann Navarro, HTML Writers Guild<br /> -Zach Nies, Quark<br /> -Dave Raggett, W3C/HP (W3C lead for HTML)<br /> -Patrick Schmitz, Microsoft<br /> -Sebastian Schnitzenbaumer, Stack Overflow<br /> -Chris Wilson, Microsoft<br /> -Ted Wugofski, Gateway 2000<br /> -Dan Zigmond, WebTV Networks</dd> -</dl> - -<!--OddPage--> -<h1><a name="refs" id="refs">Appendix E. References</a></h1> - -<p><b>This appendix is informative.</b></p> - -<dl> - -<dt><a name="ref-css2" id="ref-css2"><b>[CSS2]</b></a></dt> - -<dd><a href="http://www.w3.org/TR/REC-CSS2">"Cascading Style Sheets, level 2 (CSS2) Specification"</a>, B. -Bos, H. W. Lie, C. Lilley, I. Jacobs, 12 May 1998.<br /> -Available at: <a href="http://www.w3.org/TR/REC-CSS2"> -http://www.w3.org/TR/REC-CSS2</a></dd> - -<dt><a name="ref-dom" id="ref-dom"><b>[DOM]</b></a></dt> - -<dd><a href="http://www.w3.org/TR/REC-DOM-Level-1">"Document Object Model (DOM) Level 1 Specification"</a>, Lauren -Wood <i>et al.</i>, 1 October 1998.<br /> -Available at: <a href="http://www.w3.org/TR/REC-DOM-Level-1"> -http://www.w3.org/TR/REC-DOM-Level-1</a></dd> - -<dt><a name="ref-html4" id="ref-html4"><b>[HTML]</b></a></dt> - -<dd><a href="http://www.w3.org/TR/1999/PR-html40-19990824">"HTML 4.01 Specification"</a>, D. Raggett, A. Le Hors, I. -Jacobs, 24 August 1999.<br /> -Available at: <a href="http://www.w3.org/TR/1999/PR-html40-19990824"> -http://www.w3.org/TR/1999/PR-html40-19990824</a></dd> - -<dt><a name="ref-posix" id="ref-posix"><b>[POSIX.1]</b></a></dt> - -<dd>"ISO/IEC 9945-1:1990 Information Technology - Portable -Operating System Interface (POSIX) - Part 1: System Application -Program Interface (API) [C Language]", Institute of Electrical -and Electronics Engineers, Inc, 1990.</dd> - -<dt><a name="ref-rfc2046" id="ref-rfc2046"><b> -[RFC2046]</b></a></dt> - -<dd><a href="http://www.ietf.org/rfc/rfc2046.txt">"RFC2046: Multipurpose Internet Mail Extensions (MIME) Part -Two: Media Types"</a>, N. Freed and N. Borenstein, November -1996.<br /> -Available at <a href="http://www.ietf.org/rfc/rfc2046.txt"> -http://www.ietf.org/rfc/rfc2046.txt</a>. Note that this RFC -obsoletes RFC1521, RFC1522, and RFC1590.</dd> - -<dt><a name="ref-rfc2119" id="ref-rfc2119"><b> -[RFC2119]</b></a></dt> - -<dd><a href="http://www.ietf.org/rfc/rfc2119.txt">"RFC2119: Key words for use in RFCs to Indicate Requirement -Levels"</a>, S. Bradner, March 1997.<br /> -Available at: <a href="http://www.ietf.org/rfc/rfc2119.txt"> -http://www.ietf.org/rfc/rfc2119.txt</a></dd> - -<dt><a name="ref-rfc2376" id="ref-rfc2376"><b> -[RFC2376]</b></a></dt> - -<dd><a href="http://www.ietf.org/rfc/rfc2376.txt">"RFC2376: XML Media Types"</a>, E. Whitehead, M. Murata, July -1998.<br /> -Available at: <a href="http://www.ietf.org/rfc/rfc2376.txt"> -http://www.ietf.org/rfc/rfc2376.txt</a></dd> - -<dt><a name="ref-rfc2396" id="ref-rfc2396"><b> -[RFC2396]</b></a></dt> - -<dd><a href="http://www.ietf.org/rfc/rfc2396.txt">"RFC2396: Uniform Resource Identifiers (URI): Generic -Syntax"</a>, T. Berners-Lee, R. Fielding, L. Masinter, August -1998.<br /> -This document updates RFC1738 and RFC1808.<br /> -Available at: <a href="http://www.ietf.org/rfc/rfc2396.txt"> -http://www.ietf.org/rfc/rfc2396.txt</a></dd> - -<dt><a name="ref-xml" id="ref-xml"><b>[XML]</b></a></dt> - -<dd><a href="http://www.w3.org/TR/REC-xml">"Extensible Markup Language (XML) 1.0 Specification"</a>, T. -Bray, J. Paoli, C. M. Sperberg-McQueen, 10 February 1998.<br /> -Available at: <a href="http://www.w3.org/TR/REC-xml"> -http://www.w3.org/TR/REC-xml</a></dd> - -<dt><a name="ref-xmlns" id="ref-xmlns"><b>[XMLNAMES]</b></a></dt> - -<dd><a href="http://www.w3.org/TR/REC-xml-names">"Namespaces in XML"</a>, T. Bray, D. Hollander, A. Layman, 14 -January 1999.<br /> -XML namespaces provide a simple method for qualifying names used -in XML documents by associating them with namespaces identified -by URI.<br /> -Available at: <a href="http://www.w3.org/TR/REC-xml-names"> -http://www.w3.org/TR/REC-xml-names</a></dd> - -</dl> -<p><a href="http://www.w3.org/WAI/WCAG1AAA-Conformance" title="Explanation of Level Triple-A Conformance"> -<img height="32" width="88" src="wcag1AAA.gif" alt="Level Triple-A conformance icon, W3C-WAI Web Content Accessibility Guidelines 1.0" /></a></p> -<div class="navbar"> - <hr /> - <a href="#toc">table of contents</a> -</div> -</body> -</html> |