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<!DOCTYPE html>
<html lang=en>
<head profile="http://www.w3.org/2006/03/hcard">
<meta content="text/html; charset=UTF-8" http-equiv=Content-Type>
<title>CSS Hierarchies Module Level 3</title>
<!--
<link href="http://purl.org/dc/terms/" rel="schema.dcterms">
<link href="http://www.w3.org/Consortium/Legal/ipr-notice#Copyright" rel="dcterms.rights">
-->
<meta content="CSS Hierarchies Module Level 3" name=dcterms.title>
<meta content=text name=dcterms.type>
<meta content=2013-03-18 name=dcterms.issued>
<meta content="http://dev.w3.org/csswg/css3-hierarchies/ <!--"
name=dcterms.creator>
<meta content=W3C name=dcterms.publisher>
<meta content="http://dev.w3.org/csswg/css3-hierarchies/"
name=dcterms.identifier>
<link href="../default.css" rel=stylesheet type="text/css">
<link href="../csslogo.ico" rel="shortcut icon" type="image/x-icon">
<link href="http://www.w3.org/StyleSheets/TR/w3c-unofficial" rel=stylesheet
type="text/css">
<style type="text/css">
/* delete this block when you've cleared out all the .replaceme elements */
.replaceme {
border: solid red;
padding: 0 0.5em;
margin: 0 0.1em;
background: yellow;
color: green;
}
.replaceme:before {
content: "FIXME(";
color: black;
}
.replaceme:after {
content: ")";
color: black;
}
</style>
<style>
pre.idl { border:solid thin; background:#eee; color:#000; padding:0.5em }
pre.idl :link, pre.idl :visited { color:inherit; background:transparent }
</style>
<body>
<div class=head> <!--begin-logo-->
<p><a href="http://www.w3.org/"><img alt=W3C height=48
src="http://www.w3.org/Icons/w3c_home" width=72></a> <!--end-logo-->
<h1>CSS Hierarchies Module Level 3</h1>
<h2 class="no-num no-toc" id=unofficial-proposal-draft-date>Unofficial
Proposal Draft 18 March 2013</h2>
<dl>
<dt>This version:
<!--<dd><a href="http://dev.w3.org/csswg/css3-hierarchies/">http://dev.w3.org/csswg/css3-hierarchies/</a>-->
<dd><a
href="//dev.w3.org/csswg/css3-hierarchies/">http://dev.w3.org/csswg/css3-hierarchies/</a>
<dt>Latest version:
<!--<dd><a href="http://www.w3.org/TR/css3-hierarchies/">http://www.w3.org/TR/css3-hierarchies/</a>-->
<dd><a
href="//www.w3.org/TR/css3-hierarchies/">http://www.w3.org/TR/css3-hierarchies/</a>
<dt>Feedback:</dt>
<dd><a href="mailto:www-style@w3.org?subject=%5Bcss-hierarchies%5D%20feedback"
>www-style@w3.org</a>
with subject line “<kbd>[css-hierarchies]
<var>… message topic …</var></kbd>”
(<a rel="discussion" href="http://lists.w3.org/Archives/Public/www-style/"
>archives</a>)
<dt>Editor's draft:
<dd><a
href="//dev.w3.org/csswg/css3-hierarchies/">http://dev.w3.org/csswg/css3-hierarchies/</a>
<!--
<dt>Previous version:
<dd><a href="http://www.w3.org/PreviousVersionURI">
http://www.w3.org/PreviousVersionURI</a>
-->
<dt>Editors:
<dd class=vcard><span class=fn>Shane Stephens</span>, <span
class=org>Google, Inc.</span>, <span class=email>shans@google.com</span>
<dd class=vcard> <a href="http://xanthir.com/contact/" rel=url> <span
class=fn>Tab Atkins Jr.</span>, </a> <span class=org>Google, Inc.</span>
</dl>
<!--begin-copyright-->
<p class=copyright><a
href="http://www.w3.org/Consortium/Legal/ipr-notice#Copyright"
rel=license>Copyright</a> © 2013 <a href="http://www.w3.org/"><abbr
title="World Wide Web Consortium">W3C</abbr></a><sup>®</sup> (<a
href="http://www.csail.mit.edu/"><abbr
title="Massachusetts Institute of Technology">MIT</abbr></a>, <a
href="http://www.ercim.eu/"><abbr
title="European Research Consortium for Informatics and Mathematics">ERCIM</abbr></a>,
<a href="http://www.keio.ac.jp/">Keio</a>, <a
href="http://ev.buaa.edu.cn/">Beihang</a>), All Rights Reserved. W3C <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>
and <a
href="http://www.w3.org/Consortium/Legal/copyright-documents">document
use</a> rules apply.</p>
<!--end-copyright-->
<hr title="Separator for header">
</div>
<details class=obsolete open=open> <summary>Not Ready For
Implementation</summary>
<p> This spec is not yet ready for implementation. It exists in this
repository to record the ideas and promote discussion.
<p> Before attempting to implement this spec, please contact the CSSWG at
www-style@w3.org.
</details>
<h2 class="no-num no-toc" id=abstract>Abstract</h2>
<p>CSS is a language for describing the rendering of structured documents
(such as HTML and XML) on screen, on paper, in speech, etc. This module
contains the features of CSS level 3 relating to the hierarchical nesting
of style rules. It includes and extends the functionality of CSS level 2
<a href="#CSS21" rel=biblioentry>[CSS21]<!--{{!CSS21}}--></a>, which
builds on CSS level 1 <a href="#CSS1"
rel=biblioentry>[CSS1]<!--{{CSS1}}--></a>. The main extension compared to
level 2 is the ability to nest a style rule within another rule, allowing
greater modularisation and readibility of CSS documents.
<h2 class="no-num no-toc" id=status>Status of this document</h2>
<p><strong>This document is purely an Editor's Draft. It has not yet been
adopted by the Working Group, and should not be considered to be part of
CSS.</strong>
<p>The following features are at risk: …
<h2 class="no-num no-toc" id=contents>Table of contents</h2>
<!--begin-toc-->
<ul class=toc>
<li><a href="#intro"><span class=secno>1. </span> Introduction</a>
<ul class=toc>
<li><a href="#placement"><span class=secno>1.1. </span> Module
Interactions</a>
<li><a href="#values"><span class=secno>1.2. </span> Values</a>
<li><a href="#motivation"><span class=secno>1.3. </span> Motivation</a>
</ul>
<li><a href="#nesting-selector"><span class=secno>2. </span> The &
Selector</a>
<li><a href="#Grammar"><span class=secno>3. </span> Grammar
modifications</a>
<ul class=toc>
<li><a href="#css-2-grammar"><span class=secno>3.1. </span> Core CSS
Grammar</a>
<li><a href="#selectors4-grammar"><span class=secno>3.2. </span>
Selectors 4 Grammar</a>
<li><a href="#selectors4-lexical-scanner"><span class=secno>3.3. </span>
Selectors 4 Lexical Scanner</a>
</ul>
<li><a href="#cssom"><span class=secno>4. </span> CSS Object Model
Modifications</a>
<li><a href="#conformance"><span class=secno>5. </span> Conformance</a>
<ul class=toc>
<li><a href="#conventions"><span class=secno>5.1. </span> Document
Conventions</a>
<li><a href="#conformance-classes"><span class=secno>5.2. </span>
Conformance Classes</a>
<li><a href="#partial"><span class=secno>5.3. </span> Partial
Implementations</a>
<li><a href="#experimental"><span class=secno>5.4. </span> Experimental
Implementations</a>
<li><a href="#testing"><span class=secno>5.5. </span>Non-Experimental
Implementations</a>
<li><a href="#cr-exit-criteria"><span class=secno>5.6. </span> CR Exit
Criteria</a>
</ul>
<li class=no-num><a href="#acknowledgments">Acknowledgments</a>
<li class=no-num><a href="#references">References</a>
<ul class=toc>
<li class=no-num><a href="#normative-references">Normative
references</a>
<li class=no-num><a href="#other-references">Other references</a>
</ul>
<li class=no-num><a href="#index">Index</a>
</ul>
<!--end-toc-->
<h2 id=intro><span class=secno>1. </span> Introduction</h2>
<p><em>This section is not normative.</em>
<p>CSS beyond level 2 is a set of modules, divided up to allow the
specifications to develop incrementally, along with their implementations.
This specification is one of those modules.
<p>This module describes support for nesting a style rule within another
style rule, allowing the inner rule's selector to reference the elements
matched by the outer rule. This feature allows related styles to be
aggregated into a single structure within the CSS document, improving
readability and maintainability.
<h3 id=placement><span class=secno>1.1. </span> Module Interactions</h3>
<p>This module introduces new parser rules that extend the <a href="#CSS21"
rel=biblioentry>[CSS21]<!--{{!CSS21}}--></a> parser model. This module
introduces new parser rules that extend the [[CSS4SELECTORS]] module.
<h3 id=values><span class=secno>1.2. </span> Values</h3>
<p>This specification does not define any new properties or values.
<h3 id=motivation><span class=secno>1.3. </span> Motivation</h3>
<p>CSS Rules for even moderately complicated web pages include lots of
duplication for the purpose of styling related content. For example, here
is a portion of the CSS markup for one version of the <a href="#CSS3COLOR"
rel=biblioentry>[CSS3COLOR]<!--{{CSS3COLOR}}--></a> module:
<div class=example>
<pre>
table.colortable td {text-align:center }
table.colortable td.c { text-transform:uppercase }
table.colortable td:first-child, table.colortable td:first-child+td { border:1px solid black }
table.colortable th {text-align:center; background:black; color:white }
table.tprofile th.title {background:gray; color:white}
table.tprofile th { width:29%;padding:2px }
table.tprofile td { width:71%;padding:2px }
table.hslexample { background: #808080; padding:1em; margin:0; float:left; }
table.hslexample td,table.hslexample th { font-size:smaller;width:3em }</pre>
</div>
<p>Hierarchies allow the grouping of related style rules, like this:
<div class=example>
<pre>
table {
&.colortable {
& td {
text-align:center
&.c { text-transform:uppercase }
&:first-child, &:first-child + td { border:1px solid black }
}
& th {text-align:center; background:black; color:white }
&.tprofile {
& th {
width:29%;padding:2px;
&.title {background:gray; color:white}
}
& td { width:71%;padding:2px }
}
&.hslexample {
background: #808080; padding:1em; margin:0; float:left;
& td, & th { font-size:smaller;width:3em }
}
}</pre>
</div>
<p>Besides removing duplication, the grouping of related rules improves the
readability and maintainability of the resulting CSS.
<h2 id=nesting-selector><span class=secno>2. </span> The & Selector</h2>
<p>This specification provides a mechanism that allows for the nesting of
style rules within other style rules. A nested style rule can used
anywhere that a declaration can be used.
<p>In order to accomplish nesting, this specification defines a new simple
selector called the nesting selector, represented in selectors by the
‘<code class=css>&</code>’ character. All complex selectors in the
selector lists of nested rule sets must start with the nesting selector.
The nesting selector represents the elements matched by the parent rule
set's selector list.
<p class=issue>Introducing the ‘<code class=css>&</code>’ character
will cause issues with CSS embedded directly in XML, as it's the first
character used in CSS syntax that either requires escaping or using CDATA.
Do we need to change this?
<div class=example>
<p>The following example using Hierarchies:
<pre>
div {
& .keyword {color: red;}
&:hover {background-color: rgb(200, 255, 255);}
}</pre>
<p>...produces the same results as the following CSS:
<pre>
div .keyword {color:red;}
div:hover {background-color: rgb(200, 255, 255);}</pre>
</div>
<div class=example>
<p>The following example using Hierarchies:
<pre>
div, p {
& .keyword, & .constant {color: red;}
}</pre>
<p>...produces the same results as the following CSS:
<pre>
div .keyword, div .constant, p .keyword, p .constant {
color:red;
}</pre>
</div>
<p>Multiple style rules can be embedded within a style rule. Style rules
can be embedded arbitrarily deeply. Embedded style rules and properties
can both appear in a single declaration block, and in any order.
<div class=example>
<p>The following example using Hierarchies:
<pre>
div, p {
& .keyword {color: green;}
font-size: 10px;
& .constant {
color: red;
&:hover:after { content: " [" attr(value) "]";}
background-color: green;
}
}</pre>
<p>...produces the same results as the following CSS:
<pre>
div, p {font-size: 10px;}
div .keyword, p .keyword {color: green;}
div .constant, p .constant {color: red; background-color: green;}
div .constant:hover:after, p .constant:hover:after {content: " [" attr(value) "]";}</pre>
</div>
<p class=note>Note: Though it's unlikely that stylesheets authored with
Hierarchies will be useful in legacy user agents, as the nested sections
will be ignored by the error-handling rules, authors can minimize the
damage caused by error-recovery by always putting properties before nested
rules.
<h2 id=Grammar><span class=secno>3. </span> Grammar modifications</h2>
<p>This specification alters the CSS Core Grammar and the Selectors
grammar.
<h3 id=css-2-grammar><span class=secno>3.1. </span> Core CSS Grammar</h3>
<p>The following modifications are required to the <a href="#CSS21"
rel=biblioentry>[CSS21]<!--{{!CSS21}}--></a> grammar as defined in Section
4.1.1.
<p>The ruleset rule is changed to:
<pre>ruleset : selectors_group? ruleset-body</pre>
<p>The following rules are added:
<pre>
ruleset-body : '{' S* ruleitem? [ ';' S* ruleitem? ]* '}' S*
ruleitem : declaration | nested-ruleset
nested-ruleset : nested-selectors-group ruleset-body</pre>
<h3 id=selectors4-grammar><span class=secno>3.2. </span> Selectors 4
Grammar</h3>
<p>The following modifications are required to the [[!CSS4SELECTORS]]
grammar as defined in Section 16.1.
<p>The following rules are added:
<pre>
nested-selectors-group : nested-selector [ COMMA S* nested-selector ]
nested-selector : nested-compound-selector [ combinator compound-selector ]*
nested-compound-selector : NEST [ HASH | class | attrib | pseudo | negation ]*</pre>
<h3 id=selectors4-lexical-scanner><span class=secno>3.3. </span> Selectors
4 Lexical Scanner</h3>
<p>The following modifications are required to the [[!CSS4SELECTORS]]
lexical scanner as defined in Section 16.2.
<p>Immediately below:
<pre>"-->" return CDC;</pre>
<p>the following rule is inserted:
<pre>"&" return NEST;</pre>
<h2 id=cssom><span class=secno>4. </span> CSS Object Model Modifications</h2>
<p>The following attribute is required to be added to the CSSStyleRule
object defined in Section 6.4.3 of <a href="#CSSOM"
rel=biblioentry>[CSSOM]<!--{{!CSSOM}}--></a>:
<pre class=idl>
interface CSSStyleRule : CSSRule {
attribute DOMString selectorText;
<ins>readonly attribute DOMString expandedSelectorText;</ins>
<ins>readonly attribute CSSRuleList cssRules;</ins>
readonly attribute CSSStyleDeclaration style;
};</pre>
<p>The <code>cssRules</code> attribute must return a
<code>CSSRuleList</code> object for the list of CSS rules specified within
the style rule.
<p>The <code>expandedSelectorText</code> attribute must return a
<code>DOMString</code> object containing the result of replacing the
‘<code class=css>&</code>’ selector in the
<code>selectorText</code> attribute with the
<code>expandedSelectorText</code> attribute from the parent rule. If the
rule has no parent rule, the <code>expandedSelectorText</code> attribute
must return a <code>DOMString</code> object containing the same text as
the <code>selectorText</code> attribute.
<p class=issue>The OM here is meant to reflect the OM for ‘<code
class=css>@media</code>’ rules. In particular, the lack of a link from a
rule to its parent matches rules nested in ‘<code
class=css>@media</code>’. Should we add such a property to both of
these?
<h2 id=conformance><span class=secno>5. </span> Conformance</h2>
<h3 id=conventions><span class=secno>5.1. </span> Document Conventions</h3>
<p>Conformance requirements are expressed with a combination of descriptive
assertions and RFC 2119 terminology. The key words “MUST”, “MUST
NOT”, “REQUIRED”, “SHALL”, “SHALL NOT”, “SHOULD”,
“SHOULD NOT”, “RECOMMENDED”, “MAY”, and “OPTIONAL” in the
normative parts of this document are to be interpreted as described in RFC
2119. However, for readability, these words do not appear in all uppercase
letters in this specification.
<p>All of the text of this specification is normative except sections
explicitly marked as non-normative, examples, and notes. <a
href="#RFC2119" rel=biblioentry>[RFC2119]<!--{{!RFC2119}}--></a>
<p>Examples in this specification are introduced with the words “for
example” or are set apart from the normative text with
<code>class="example"</code>, like this:
<div class=example>
<p>This is an example of an informative example.
</div>
<p>Informative notes begin with the word “Note” and are set apart from
the normative text with <code>class="note"</code>, like this:
<p class=note>Note, this is an informative note.
<h3 id=conformance-classes><span class=secno>5.2. </span> Conformance
Classes</h3>
<p>Conformance to <var class=replaceme>CSS TEMPLATE Module</var> is defined
for three conformance classes:
<dl>
<dt><dfn id=style-sheet title="style sheet!!as conformance class">style
sheet</dfn>
<dd>A <a href="http://www.w3.org/TR/CSS21/conform.html#style-sheet">CSS
style sheet</a>.
<dt><dfn id=renderer>renderer</dfn>
<dd>A <a href="http://www.w3.org/TR/CSS21/conform.html#user-agent">UA</a>
that interprets the semantics of a style sheet and renders documents that
use them.
<dt><dfn id=authoring-tool>authoring tool</dfn>
<dd>A <a href="http://www.w3.org/TR/CSS21/conform.html#user-agent">UA</a>
that writes a style sheet.
</dl>
<p>A style sheet is conformant to <var class=replaceme>CSS TEMPLATE
Module</var> if all of its declarations that use properties defined in
this module have values that are valid according to the generic CSS
grammar and the individual grammars of each property as given in this
module.
<p>A renderer is conformant to <var class=replaceme>CSS TEMPLATE
Module</var> if, in addition to interpreting the style sheet as defined by
the appropriate specifications, it supports all the features defined by
<var class=replaceme>CSS TEMPLATE Module</var> by parsing them correctly
and rendering the document accordingly. However, the inability of a UA to
correctly render a document due to limitations of the device does not make
the UA non-conformant. (For example, a UA is not required to render color
on a monochrome monitor.)
<p>An authoring tool is conformant to <var class=replaceme>CSS TEMPLATE
Module</var> if it writes style sheets that are syntactically correct
according to the generic CSS grammar and the individual grammars of each
feature in this module, and meet all other conformance requirements of
style sheets as described in this module.
<h3 id=partial><span class=secno>5.3. </span> Partial Implementations</h3>
<p>So that authors can exploit the forward-compatible parsing rules to
assign fallback values, CSS renderers <strong>must</strong> treat as
invalid (and <a
href="http://www.w3.org/TR/CSS21/conform.html#ignore">ignore as
appropriate</a>) any at-rules, properties, property values, keywords, and
other syntactic constructs for which they have no usable level of support.
In particular, user agents <strong>must not</strong> selectively ignore
unsupported component values and honor supported values in a single
multi-value property declaration: if any value is considered invalid (as
unsupported values must be), CSS requires that the entire declaration be
ignored.
<h3 id=experimental><span class=secno>5.4. </span> Experimental
Implementations</h3>
<p>To avoid clashes with future CSS features, the CSS2.1 specification
reserves a <a
href="http://www.w3.org/TR/CSS21/syndata.html#vendor-keywords">prefixed
syntax</a> for proprietary and experimental extensions to CSS.
<p>Prior to a specification reaching the Candidate Recommendation stage in
the W3C process, all implementations of a CSS feature are considered
experimental. The CSS Working Group recommends that implementations use a
vendor-prefixed syntax for such features, including those in W3C Working
Drafts. This avoids incompatibilities with future changes in the draft.
<h3 id=testing><span class=secno>5.5. </span>Non-Experimental
Implementations</h3>
<p>Once a specification reaches the Candidate Recommendation stage,
non-experimental implementations are possible, and implementors should
release an unprefixed implementation of any CR-level feature they can
demonstrate to be correctly implemented according to spec.
<p>To establish and maintain the interoperability of CSS across
implementations, the CSS Working Group requests that non-experimental CSS
renderers submit an implementation report (and, if necessary, the
testcases used for that implementation report) to the W3C before releasing
an unprefixed implementation of any CSS features. Testcases submitted to
W3C are subject to review and correction by the CSS Working Group.
<p>Further information on submitting testcases and implementation reports
can be found from on the CSS Working Group's website at <a
href="http://www.w3.org/Style/CSS/Test/">http://www.w3.org/Style/CSS/Test/</a>.
Questions should be directed to the <a
href="http://lists.w3.org/Archives/Public/public-css-testsuite">public-css-testsuite@w3.org</a>
mailing list.
<h3 id=cr-exit-criteria><span class=secno>5.6. </span> CR Exit Criteria</h3>
<p class=issue>[Change or remove the following CR exit criteria if the spec
is not a module, but, e.g., a Note or a profile. This text was <a
href="http://www.w3.org/Style/CSS/Tracker/actions/44"> decided on
2008-06-04.</a>]
<p> For this specification to be advanced to Proposed Recommendation, there
must be at least two independent, interoperable implementations of each
feature. Each feature may be implemented by a different set of products,
there is no requirement that all features be implemented by a single
product. For the purposes of this criterion, we define the following
terms:
<dl>
<dt>independent
<dd>each implementation must be developed by a different party and cannot
share, reuse, or derive from code used by another qualifying
implementation. Sections of code that have no bearing on the
implementation of this specification are exempt from this requirement.
<dt>interoperable
<dd>passing the respective test case(s) in the official CSS test suite,
or, if the implementation is not a Web browser, an equivalent test. Every
relevant test in the test suite should have an equivalent test created if
such a user agent (UA) is to be used to claim interoperability. In
addition if such a UA is to be used to claim interoperability, then there
must one or more additional UAs which can also pass those equivalent
tests in the same way for the purpose of interoperability. The equivalent
tests must be made publicly available for the purposes of peer review.
<dt>implementation
<dd>a user agent which:
<ol class=inline>
<li>implements the specification.
<li>is available to the general public. The implementation may be a
shipping product or other publicly available version (i.e., beta
version, preview release, or “nightly build”). Non-shipping product
releases must have implemented the feature(s) for a period of at least
one month in order to demonstrate stability.
<li>is not experimental (i.e., a version specifically designed to pass
the test suite and is not intended for normal usage going forward).
</ol>
</dl>
<p>The specification will remain Candidate Recommendation for at least six
months.
<h2 class=no-num id=acknowledgments>Acknowledgments</h2>
<p><var class=replaceme>[acknowledgments]</var>
<h2 class=no-num id=references>References</h2>
<h3 class=no-num id=normative-references>Normative references</h3>
<!--begin-normative-->
<!-- Sorted by label -->
<dl class=bibliography>
<dt style="display: none"><!-- keeps the doc valid if the DL is empty -->
<!---->
<dt id=CSS21>[CSS21]
<dd>Bert Bos; et al. <a
href="http://www.w3.org/TR/2011/REC-CSS2-20110607/"><cite>Cascading Style
Sheets Level 2 Revision 1 (CSS 2.1) Specification.</cite></a> 7 June
2011. W3C Recommendation. URL: <a
href="http://www.w3.org/TR/2011/REC-CSS2-20110607/">http://www.w3.org/TR/2011/REC-CSS2-20110607/</a>
</dd>
<!---->
<dt id=CSSOM>[CSSOM]
<dd>Anne van Kesteren. <a
href="http://www.w3.org/TR/2011/WD-cssom-20110712/"><cite>CSSOM.</cite></a>
12 July 2011. W3C Working Draft. (Work in progress.) URL: <a
href="http://www.w3.org/TR/2011/WD-cssom-20110712/">http://www.w3.org/TR/2011/WD-cssom-20110712/</a>
</dd>
<!---->
<dt id=RFC2119>[RFC2119]
<dd>S. Bradner. <a href="http://www.ietf.org/rfc/rfc2119.txt"><cite>Key
words for use in RFCs to Indicate Requirement Levels.</cite></a> Internet
RFC 2119. URL: <a
href="http://www.ietf.org/rfc/rfc2119.txt">http://www.ietf.org/rfc/rfc2119.txt</a>
</dd>
<!---->
</dl>
<!--end-normative-->
<h3 class=no-num id=other-references>Other references</h3>
<!--begin-informative-->
<!-- Sorted by label -->
<dl class=bibliography>
<dt style="display: none"><!-- keeps the doc valid if the DL is empty -->
<!---->
<dt id=CSS1>[CSS1]
<dd>Håkon Wium Lie; Bert Bos. <a
href="http://www.w3.org/TR/2008/REC-CSS1-20080411"><cite>Cascading Style
Sheets (CSS1) Level 1 Specification.</cite></a> 11 April 2008. W3C
Recommendation. URL: <a
href="http://www.w3.org/TR/2008/REC-CSS1-20080411">http://www.w3.org/TR/2008/REC-CSS1-20080411&
133E
lt;/a>
</dd>
<!---->
<dt id=CSS3COLOR>[CSS3COLOR]
<dd>Tantek Çelik; Chris Lilley; L. David Baron. <a
href="http://www.w3.org/TR/2011/REC-css3-color-20110607"><cite>CSS Color
Module Level 3.</cite></a> 7 June 2011. W3C Recommendation. URL: <a
href="http://www.w3.org/TR/2011/REC-css3-color-20110607">http://www.w3.org/TR/2011/REC-css3-color-20110607</a>
</dd>
<!---->
</dl>
<!--end-informative-->
<h2 class=no-num id=index>Index</h2>
<!--begin-index-->
<ul class=indexlist>
<li>authoring tool, <a href="#authorin
4EB9
g-tool"
title="section 5.2."><strong>5.2.</strong></a>
<li>renderer, <a href="#renderer"
title="section 5.2."><strong>5.2.</strong></a>
<li>style sheet
<ul>
<li>as conformance class, <a href="#style-sheet"
title="section 5.2."><strong>5.2.</strong></a>
</ul>
</ul>
<!--end-index-->
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