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<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
"http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<title>CSS Lists and Counters Module Level 3</title>
<meta content="text/html; charset=utf-8" http-equiv=Content-Type>
<link href="http://dev.w3.org/csswg/default.css" rel=stylesheet
type="text/css">
<style>
p { text-indent: 0 !important; margin: .5em 0; }
code.inline { white-space: pre-line; }
.alphabetic-example { font-family: monospace; font-size: 90%; margin: 1em 0 1em 2em; }
.alphabetic-example > span { display: inline-block; width: 50px;}
.alphabetic-example > span > img { width: 16px; height: 16px; }
</style>
<link href="http://www.w3.org/StyleSheets/TR/W3C-ED" rel=stylesheet
type="text/css">
<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 Lists and Counters Module Level 3</h1>
<h2 class="no-num no-toc" id=longstatus-date>Editor's Draft 2 May 2011</h2>
<dl>
<dt>This version:
<dd><!-- <a href="http://www.w3.org/TR/2011/WD-css3-lists-20110502">http://www.w3.org/TR/2011/WD-css3-lists-20110502</a></dd> -->
<a
href="http://dev.w3.org/csswg/css3-lists/">http://dev.w3.org/csswg/css3-lists/</a>
<dt>Latest version:
<dd><a
href="http://www.w3.org/TR/css3-lists/">http://www.w3.org/TR/css3-lists/</a>
<dt>Previous version:
<dd><a
href="http://www.w3.org/TR/2002/WD-css3-lists-20021107/">http://www.w3.org/TR/2002/WD-css3-lists-20021107/</a>
<dt>Editor:
<dd><a href="http://www.xanthir.com/contact">Tab Atkins Jr.</a>, Google
Inc.
<dt>Previous Editors:</dt>
<!-- in the order tantek requested -->
<dd>Ian Hickson, <a href="mailto:ian@hixie.ch">ian@hixie.ch</a>
<dd><span lang=tr>Tantek Çelı̇k</span>, Microsoft
Corporation, <a
href="mailto:tantekc@microsoft.com">tantekc@microsoft.com</a>
<dt>Contributors:</dt>
<!-- in order of volume of input -->
<dd>Simon Montagu, AOL-TW/Netscape, <a
href="mailto:smontagu@netscape.com">smontagu@netscape.com</a>
<dd>Daniel Yacob, <a href="mailto:yacob@geez.org">yacob@geez.org</a>
<dd>Christopher Hoess, <a
href="mailto:choess@stwing.upenn.edu">choess@stwing.upenn.edu</a>
<dd>Daniel Glazman, AOL-TW/Netscape, <a
href="mailto:glazman@netscape.com">glazman@netscape.com</a>
</dl>
<!--begin-copyright-->
<p class=copyright><a
href="http://www.w3.org/Consortium/Legal/ipr-notice#Copyright"
rel=license>Copyright</a> © 2011 <a
href="http://www.w3.org/"><acronym title="World Wide Web
Consortium">W3C</acronym></a><sup>®</sup> (<a
href="http://www.csail.mit.edu/"><acronym title="Massachusetts Institute
of Technology">MIT</acronym></a>, <a href="http://www.ercim.eu/"><acronym
title="European Research Consortium for Informatics and
Mathematics">ERCIM</acronym></a>, <a
href="http://www.keio.ac.jp/">Keio</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>
<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 draft
contains the features of CSS level 3 relating to list styling. 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 extensions compared to
level 2 are a pseudo-element representing the list marker, a new
‘<a href="#hanging"><code class=css>hanging</code></a>’ value
for ‘<a href="#list-style-position"><code
class=property>list-style-position</code></a>’, and a method for
authors to define their own list-styles.
<h2 class="no-num no-toc" id=status> Status of this document</h2>
<!--begin-status-->
<p>This is a public copy of the editors' draft. It is provided for
discussion only and may change at any moment. Its publication here does
not imply endorsement of its contents by W3C. Don't cite this document
other than as work in progress.
<p>The (<a
href="http://lists.w3.org/Archives/Public/www-style/">archived</a>) public
mailing list <a
href="mailto:www-style@w3.org?Subject=%5Bcss3-lists%5D%20PUT%20SUBJECT%20HERE">
www-style@w3.org</a> (see <a
href="http://www.w3.org/Mail/Request">instructions</a>) is preferred for
discussion of this specification. When sending e-mail, please put the text
“css3-lists” in the subject, preferably like this:
“[<!---->css3-lists<!---->] <em>…summary of
comment…</em>”
<p>This document was produced by the <a href="/Style/CSS/members">CSS
Working Group</a> (part of the <a href="/Style/">Style Activity</a>).
<p>This document was produced by a group operating under the <a
href="/Consortium/Patent-Policy-20040205/">5 February 2004 W3C Patent
Policy</a>. W3C maintains a <a href="/2004/01/pp-impl/32061/status"
rel=disclosure>public list of any patent disclosures</a> made in
connection with the deliverables of the group; that page also includes
instructions for disclosing a patent. An individual who has actual
knowledge of a patent which the individual believes contains <a
href="/Consortium/Patent-Policy-20040205/#def-essential">Essential
Claim(s)</a> must disclose the information in accordance with <a
href="/Consortium/Patent-Policy-20040205/#sec-Disclosure">section 6 of the
W3C Patent Policy</a>.</p>
<!--end-status-->
<h2 class="no-num no-toc" id=contents> Table of contents</h2>
<!--begin-toc-->
<ul class=toc>
<li><a href="#introduction"><span class=secno>1. </span> Introduction</a>
<li><a href="#declaring-a-list-item"><span class=secno>2. </span>
Declaring a List Item</a>
<li><a href="#marker-content"><span class=secno>3. </span> Marker Content:
The ‘<code class=property>list-style-type</code>’ and
‘<code class=property>list-style-image</code>’ properties</a>
<li><a href="#list-style-position-property"><span class=secno>4. </span>
Marker Position: The ‘<code
class=property>list-style-position</code>’ property</a>
<li><a href="#list-style-property"><span class=secno>5. </span> The
‘<code class=property>list-style</code>’ shorthand
property</a>
<li><a href="#marker-pseudoelement"><span class=secno>6. </span> Markers:
The ‘<code class=css>::marker</code>’ pseudo-element</a>
<ul class=toc>
<li><a href="#content-property"><span class=secno>6.1. </span>
Generating the computed value of the ‘<code
class=property>content</code>’ property</a>
</ul>
<li><a href="#display-marker"><span class=secno>7. </span> Using Content
as Markers: the ‘<code class=css>marker</code>’ value for
‘<code class=property>display</code>’</a>
<li><a href="#predefined-counters"><span class=secno>8. </span> Predefined
Counter Styles</a>
<ul class=toc>
<li><a href="#glyph-counters"><span class=secno>8.1. </span> Glyphs</a>
<li><a href="#complex-counters"><span class=secno>8.2. </span> Complex
counter styles</a>
<ul class=toc>
<li><a href="#ethiopic-numeric"><span class=secno>8.2.1. </span> The
‘<code class=property>ethiopic-numeric</code>’ counter
style</a>
<li><a href="#cjk-counter-styles"><span class=secno>8.2.2. </span> The
Chinese longhand counter styles</a>
</ul>
</ul>
<li><a href="#counter-style"><span class=secno>9. </span> Defining Custom
Counter Styles: the ‘<code class=css>@counter-style</code>’
rule</a>
<ul class=toc>
<li><a href="#counter-style-type"><span class=secno>9.1. </span> Counter
algorithms: the ‘<code class=property>type</code>’
descriptor</a>
<ul class=toc>
<li><a href="#repeating"><span class=secno>9.1.1. </span>
repeating</a>
<li><a href="#numeric"><span class=secno>9.1.2. </span> numeric</a>
<li><a href="#alphabetic"><span class=secno>9.1.3. </span>
alphabetic</a>
<li><a href="#symbolic"><span class=secno>9.1.4. </span> symbolic</a>
<li><a href="#non-repeating"><span class=secno>9.1.5. </span>
non-repeating</a>
<li><a href="#additive"><span class=secno>9.1.6. </span> additive</a>
<li><a href="#override"><span class=secno>9.1.7. </span> override</a>
</ul>
<li><a href="#counter-style-negative"><span class=secno>9.2. </span>
Formatting negative values: the ‘<code
class=property>negative</code>’ descriptor</a>
<li><a href="#counter-style-prefix"><span class=secno>9.3. </span>
Symbols before the marker: the ‘<code
class=property>prefix</code>’ descriptor</a>
<li><a href="#counter-style-suffix"><span class=secno>9.4. </span>
Symbols after the marker: the ‘<code
class=property>suffix</code>’ descriptor</a>
<li><a href="#counter-style-range"><span class=secno>9.5. </span>
Limiting the counter scope: the ‘<code
class=property>range</code>’ descriptor</a>
<li><a href="#counter-style-fallback"><span class=secno>9.6. </span>
Defining fallback: the ‘<code
class=property>fallback</code>’ descriptor</a>
<li><a href="#counter-style-glyphs"><span class=secno>9.7. </span>
Marker characters: the ‘<code class=property>glyphs</code>’
and ‘<code class=property>additive-glyphs</code>’
descriptors</a>
</ul>
<li><a href="#html4"><span class=secno>10. </span> Sample style sheet for
HTML</a>
<li><a href="#ua-stylesheet"><span class=secno>11. </span> Appendix A:
Additional Predefined Counter Styles</a>
<li class=no-num><a href="#profiles"> Profiles</a>
<li class=no-num><a href="#acknowledgments"> Acknowledgments</a>
<li class=no-num><a href="#changes"> Changes From CSS2</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="#property-index">Property index</a>
<li class=no-num><a href="#index">Index</a>
</ul>
<!--end-toc-->
<hr>
<!-- ====================================================================== -->
<h2 id=introduction><span class=secno>1. </span> Introduction</h2>
<p>The list model in this module differs in some important ways from the
list model in CSS2, specifically in its handling of markers.
Implementation experience suggested the CSS2 model overloaded the ::before
and ::after pseudo-elements with too much behavior, while at the same time
introducing new properties when existing properties were sufficient.
<p>Most block-level elements in CSS generate one principal block box. In
this module, we discuss two CSS mechanisms that cause an element to have
an associated marker: one method associates one principal block box (for
the element's content) with a separate marker box (for decoration such as
a bullet, image, or number), and the other inserts a marker box into the
principal box. Unlike :before and :after content, the marker box cannot
affect the position of the principal box, whatever the positioning scheme.
<div class=html-example>
<p>For instance, the following example illustrates how markers may be used
to add parentheses around each numbered list item. This HTML application
and style sheet:</p>
<pre>
<!doctype html>
<html>
<head>
<title>Creating a list with markers</title>
<style>
li::marker { content: "(" counter(list-item, lower-roman) ")"; }
li { display: list-item; }
</style>
</head>
<body>
<ol>
<li>This is the first item.</li>
<li>This is the second item.</li>
<li>This is the third item.</li>
</ol>
</body>
</html>
</pre>
<p>should produce something like this:</p>
<pre>
(i) This is the first item.
(ii) This is the second item.
(iii) This is the third item.
</pre>
</div>
<p>With descendant selectors and child selectors, it's possible to specify
different marker types depending on the depth of embedded lists.
<p class=issue>A future release of this module will probably include ways
to render tree lists.</p>
<!-- ====================================================================== -->
<h2 id=declaring-a-list-item><span class=secno>2. </span> Declaring a List
Item</h2>
<p>To declare a list item, the ‘<a href="#display"><code
class=property>display</code></a>’ property should be set to
‘<code class=css>list-item</code>’. This, in addition to
generating a ‘<code class=css>::marker</code>’ pseudo-element
and enabling the properties described below for that element, causes that
element to increment the list item counter ‘<code
class=css>list-item</code>’. (This does not affect the specified or
computed values of the counter properties.)
<p>The ‘<code class=css>list-item</code>’ counter is a real
counter, and can be directly affected using the ‘<code
class=property>counter-increment</code>’ and ‘<code
class=css>counter-reset</code>’ properties. It can also be used in
the ‘<code class=css>counter()</code>’ and ‘<code
class=css>counters()</code>’ functions.
<p class=issue>The CSS3 box module may define other ‘<a
href="#display"><code class=property>display</code></a>’ values
which generate a list marker. These should also affect the ‘<code
class=css>list-item</code>’ counter.
<p>Note that this new model makes the ‘<code
class=css>marker</code>’ display type redundant. That display type
is therefore obsolete in the CSS3 Lists model.</p>
<!-- ====================================================================== -->
<h2 id=marker-content><span class=secno>3. </span> Marker Content: The
‘<a href="#list-style-type"><code
class=property>list-style-type</code></a>’ and ‘<a
href="#list-style-image"><code
class=property>list-style-image</code></a>’ properties</h2>
<table class=propdef>
<tbody>
<tr>
<th>Name:
<td><dfn id=list-style-type>list-style-type</dfn>
<tr>
<th>Value:
<td><a href="#ltstring"><b><string></b></a> | <a
href="#ltcounter-style"><b><counter-style></b></a> | inline | none
<tr>
<th>Initial:
<td>disc
<tr>
<th>Applies To:
<td>all elements with ‘<code class=css>display:
list-item</code>’
<tr>
<th>Inherited:
<td>yes
<tr>
<th>Media:
<td>visual
<tr>
<th>Computed Value:
<td>specified value
</table>
<p>When the ‘<a href="#list-style-image"><code
class=property>list-style-image</code></a>’ property is ‘<a
href="#none"><code class=css>none</code></a>’ or not a valid image,
the ‘<a href="#list-style-type"><code
class=property>list-style-type</code></a>’ property is instead used
to construct the default contents of a list item's marker.
<dl>
<dt><dfn id=ltstring><string></dfn>
<dd>The ‘<code class=css>::marker</code>’ pseudoelement must
use the provided string as its default contents.
<dt><dfn id=ltcounter-style><counter-style></dfn>
<dd>
<p>The ‘<code class=css>::marker</code>’ pseudoelement's
default contents must be the value of the ‘<code
class=css>list-item</code>’ counter, formatted according to the
given counter style. Algorithms for formatting a value according to a
counter style are given later in this spec.</p>
<p>This specification defines a method for authors to create their own
counter styles which may be used here. Additionally, many useful counter
styles are predefined in the sections on <a
href="#predefined-counters">Predefined Counter Styles</a> and <a
href="#ua-stylesheet">Additional Predefined Counter Styles</a>.</p>
<dt><dfn id=inline>inline</dfn>
<dd>The ‘<code class=css>::marker</code>’ pseudoelement's
default contents must be the textual contents of the list item's first
child that is an <i title=inline-marker-candidate>inline marker
candidate</i>, if one exists.
<dt><dfn id=none>none</dfn>
<dd>The ‘<code class=css>::marker</code>’ pseudoelement must
have no default contents. This will suppress the creation of a marker
unless the ‘<code class=css>::marker</code>’ has its contents
specified directly through the ‘<code
class=property>content</code>’ property.
</dl>
<table class=propdef>
<tbody>
<tr>
<th>Name:
<td><dfn id=list-style-image>list-style-image</dfn>
<tr>
<th>Value:
<td><image> | none
<tr>
<th>Initial
<td>none
<tr>
<th>Applies To:
<td>all elements with ‘<code class=css>display:
list-item</code>’
<tr>
<th>Inherited:
<td>yes
<tr>
<th>Media:
<td>visual
<tr>
<th>Computed Value:
<td>specified value
</table>
<p>This property sets the image that will be used as the list item marker.
When the <b><image></b> resolves to a valid image, it is used as the
default contents of ‘<code class=css>::marker</code>’ instead
of the value specified by ‘<a href="#list-style-type"><code
class=property>list-style-type</code></a>’.
<p>If the value ‘<a href="#none"><code
class=css>none</code></a>’ is provided, or the <b><image></b>
doesn't resolve to a valid image, then the default contents are given by
‘<a href="#list-style-type"><code
class=property>list-style-type</code></a>’ instead.
<div class=example>
<p>The following example sets the marker at the beginning of each list
item to be the image "ellipse.png".</p>
<pre>LI { list-style-image: url("http://www.example.com/ellipse.png") }</pre>
</div>
<!-- ====================================================================== -->
<h2 id=list-style-position-property><span class=secno>4. </span> Marker
Position: The ‘<a href="#list-style-position"><code
class=property>list-style-position</code></a>’ property</h2>
<table class=propdef>
<tbody>
<tr>
<th>Name:
<td><dfn id=list-style-position>list-style-position</dfn>
<tr>
<th>Value:
<td>inside | hanging | outside
<tr>
<th>Initial:
<td>outside
<tr>
<th>Applies To:
<td>all elements with ‘<code class=css>display:
list-item</code>’
<tr>
<th>Inherited:
<td>yes
<tr>
<th>Media:
<td>visual
<tr>
<th>Computed Value:
<td>specified value
</table>
<p>This property specifies the position of the ‘<code
class=css>::marker</code>’ pseudo-element's box in the list item.
Values have the following meanings:
<dl>
<dt><dfn id=inside>inside</dfn>
<dd>The ‘<code class=css>::marker</code>’ pseudo-element is an
inline-block element placed immediately before the ‘<code
class=css>::before</code>’ pseudo-element in the list item's
principle box, after which the element's content flows. Note that if
there is no inline content, this will create a line box, just as content
in an inline ‘<code class=css>::before</code>’ pseudo-element
would. Also note that all the properties that apply to inline elements
apply to the ‘<code class=css>::marker</code>’ pseudo-element
in this state, and this ‘<code class=css>::marker</code>’ box
participates in the inline box model in the normal manner.
<p class=issue>Inline markers have some special behavior wrt white-space
collapsing at the beginning of the list-item. I need to figure this out
and spec it. (Since I have hanging and outside markers be abspos, it
doesn't apply to them.)
<dt><dfn id=hanging>hanging</dfn>
<dd>As ‘<a href="#inside"><code class=css>inside</code></a>’,
except the marker is absolutely positioned. The marker's static position
is such that its baseline is aligned with the baseline of the first line
box in the list item, and its "end" edge is flush with the "start" edge
of the first line box in the list item. <span class=note>Note that, per
the Positioned Layout spec, absolutely positioned boxes leave behind a
‘<code class=property>placeholder</code>’ in their original
position in the box tree, which may have an effect on line-box
generation.</span>
<dt><dfn id=outside>outside</dfn>
<dd>As ‘<a href="#inside"><code class=css>inside</code></a>’,
except the marker is absolutely positioned and has the same
directionality as the list item's parent box. The marker's static
position is such that its "over" edge is flush with the edge of the list
item corresponding with the "over" edge of the list item's parent box,
and it's "end" edge is flush with the edge fo the list item corresponding
to the "start" edge of the list item's parent box.
</dl>
<p class=issue>Are the positioning rules for ‘<a
href="#hanging"><code class=css>hanging</code></a>’ and ‘<a
href="#outside"><code class=css>outside</code></a>’ good?
<p>Note that a marker is only generated if the computed value of the
‘<code class=property>content</code>’ property for the
element's ‘<code class=css>::marker</code>’ pseudo-element is
not ‘<a href="#none"><code class=css>none</code></a>’.
<div class=example>
<p>For example:
<pre class=html-example>
<!doctype html>
<html>
<head>
<title>Comparison of inside/outside position</title>
<style>
ul { list-style: outside; }
ul.compact { list-style: inside; }
</style>
</head>
<body>
<ul>
<li>first list item comes first</li>
<li>second list item comes second</li>
</ul>
<ul class=compact>
<li>first list item comes first</li>
<li>second list item comes second</li>
</ul>
</body>
</html>
</pre>
<p>The above example may be formatted as:</p>
<div class=figure>
<p><img alt="list with bullets to the left of it and list with bullets
inside" id=img-list-inout src=list-inout.gif></p>
</div>
<p>In right-to-left text, the markers would have been on the right side of
the box.</p>
</div>
<!-- ====================================================================== -->
<h2 id=list-style-property><span class=secno>5. </span> The ‘<a
href="#list-style"><code class=property>list-style</code></a>’
shorthand property</h2>
<table class=propdef>
<tbody>
<tr>
<th>Name:
<td><dfn id=list-style>list-style</dfn>
<tr>
<th>Value:
<td><‘<a href="#list-style-type"><code
class=property>list-style-type</code></a>’> || <‘<a
href="#list-style-position"><code
class=property>list-style-position</code></a>’> || <‘<a
href="#list-style-image"><code
class=property>list-style-image</code></a>’>
<tr>
<th>Initial:
<td>N/A (shorthand property)
<tr>
<th>Applies To:
<td>all elements with ‘<code class=css>display:
list-item</code>’
<tr>
<th>Media:
<td>visual
<tr>
<th>Computed Value;
<td>N/A (shorthand property)
</table>
<p>The ‘<a href="#list-style"><code
class=property>list-style</code></a>’ property is a shorthand
notation for setting the three properties ‘<a
href="#list-style-type"><code
class=property>list-style-type</code></a>’, ‘<a
href="#list-style-image"><code
class=property>list-style-image</code></a>’, and ‘<a
href="#list-style-position"><code
class=property>list-style-position</code></a>’ at the same place in
the style sheet.
<div class=example>
<p>For example:</p>
<pre>
UL { list-style: upper-roman inside } /* Any UL */
UL > UL { list-style: circle outside } /* Any UL child of a UL */
</pre>
</div>
<p>Using a value of ‘<a href="#none"><code
class=css>none</code></a>’ in the shorthand is potentially
ambiguous, as ‘<a href="#none"><code
class=css>none</code></a>’ is a valid value for both ‘<a
href="#list-style-image"><code
class=property>list-style-image</code></a>’ and ‘<a
href="#list-style-type"><code
class=property>list-style-type</code></a>’; to resolve this
ambiguity, a value of ‘<a href="#none"><code
class=css>none</code></a>’ in the shorthand must be applied to
whichever of the two properties aren't otherwise set by the shorthand.
<pre class=css-example>
list-style: none disc;
/* Sets the image to ''none'' and the type to ''disc''. */
list-style: none url(bullet.png);
/* Sets the image to ''url(bullet.png)'' and the type to ''none''. */
list-style: none;
/* Sets both image and type to ''none''. */
list-style: none disc url(bullet.png);
/* Syntax error */
</pre>
<p>Although authors may specify ‘<a href="#list-style"><code
class=property>list-style</code></a>’ information directly on list
item elements (e.g., LI in HTML), they should do so with care. The
following rules look similar, but the first declares a descendant selector
and the second a (more specific) child selector.
<pre class=example>
OL.alpha LI { list-style: lower-alpha } /* Any LI descendant of an OL */
OL.alpha > LI { list-style: lower-alpha } /* Any LI child of an OL */
</pre>
<p>Authors who use only the descendant selector may not achieve the results
they expect. Consider the following rules:
<pre class=html-example>
<!doctype html>
<html>
<head>
<title>WARNING: Unexpected results due to cascade</title>
<style>
ol.alpha li { list-style: lower-alpha; }
ul li { list-style: disc; }
</style>
</head>
<body>
<ol class=alpha>
<li>level 1
<ul>
<li>level 2</li>
</ul>
</li>
</ol>
</body>
</html>
</pre>
<p>The desired rendering would have level 1 list items with ‘<code
class=property>lower-alpha</code>’ labels and level 2 items with
‘<code class=property>disc</code>’ labels. However, the
cascading order will cause the first style rule (which includes specific
class information) to mask the second. The following rules solve the
problem by employing a child selector instead:
<pre class=example>
OL.alpha > LI { list-style: lower-alpha }
UL LI { list-style: disc }
</pre>
<p>Another solution would be to specify ‘<a href="#list-style"><code
class=property>list-style</code></a>’ information only on the list
type elements:
<pre class=example>
OL.alpha { list-style: lower-alpha }
UL { list-style: disc }
</pre>
<p>Inheritance will transfer the ‘<a href="#list-style"><code
class=property>list-style</code></a>’ values from OL and UL elements
to LI elements. This is the recommended way to specify list style
information.</p>
<!-- ====================================================================== -->
<h2 id=marker-pseudoelement><span class=secno>6. </span> Markers: The
‘<code class=css>::marker</code>’ pseudo-element</h2>
<p>Markers are created by setting an element's ‘<a
href="#display"><code class=property>display</code></a>’ property to
‘<code class=css>list-item</code>’. The ‘<code
class=css>list-item</code>’ display type is, in every other respect,
identical to the ‘<code class=css>block</code>’ display type.
The marker box is only created if the computed value of the ‘<code
class=property>content</code>’ property for the pseudo-element is
not ‘<a href="#none"><code class=css>none</code></a>’.
<p>Just like other generated content, markers generate a box when they're
created, which has margins, border, padding, and everything else a box
normally has. Markers are placed at the beginning of their superior
parent's content, immediately before a ‘<code
class=css>::before</code>’ pseudo-element on the same superior
parent. Marker boxes are inline-block by default, and so a value of
‘<code class=css>auto</code>’ for ‘<code
class=property>width</code>’ resolves to the width of the marker's
content. The value of ‘<a href="#list-style-position"><code
class=property>list-style-position</code></a>’ on the marker's
superior parent can vary the marker's directionality and the initial value
of its ‘<code class=css>position</code>’ property.
<div class=html-example>
<p>In the following example, the content is centered within a marker box
of a fixed width. This document:</p>
<pre class=html-example>
<!doctype html>
<html>
<head>
<title>Content alignment in the marker box</title>
<style>
LI::marker {
content: "(" counter(counter) ")";
width: 6em;
text-align: center;
}
LI {
display: list-item;
counter-increment: counter;
}
</style>
</head>
<body>
<ol>
<li>This is the first item.</li>
<li>This is the second item.</li>
<li>This is the third item.</li>
</ol>
</body>
</html>
</pre>
<p>should render something like this:</p>
<pre>
(1) This is the
first item.
(2) This is the
second item.
(3) This is the
third item.
</pre>
</div>
<p>The next example uses markers to number notes (paragraphs).
<div class=html-example>
<p>The following document:</p>
<pre class=html-example>
<!doctype html>
<html>
<head>
<title>Markers to create numbered notes</title>
<style>
P { margin-left: 12 em; }
P.Note::marker {
content: url("note.gif") "Note " counter(note-counter) ":";
text-align: left;
width: 10em;
}
P.Note {
display: list-item;
counter-increment: note-counter;
}
</style>
</head>
<body>
<p>This is the first paragraph in this document.</p>
<p class="Note">This is a very short document.</p>
<p>This is the end.</p>
</body>
</html>
</pre>
<p>should render something like this:</p>
<pre>
This is the first paragraph
in this document.
Note 1: This is a very short
document.
This is the end.
</pre>
</div>
<div class=html-example>
<p>The following example illustrates how markers may be offset from their
element. This HTML application and style sheet:</p>
<pre class=html-example>
<!doctype html>
<html>
<head>
<title>Marker example</title>
<style>
P { margin-left: 8em } /* Make space for counters */
LI::marker { margin: 0 3em 0 0; content: counter(list-item, lower-roman) "."; }
LI { display: list-item }
</style>
</head>
<body>
<p>This is a long preceding paragraph ...</p>
<ol>
<li>This is the first item.</li>
<li>This is the second item.</li>
<li>This is the third item.</li>
</ol>
<p>This is a long following paragraph ...</p>
</body>
</html>
</pre>
<p>should render something like this:</p>
<pre>
This is a long preceding
paragraph ...
i. This is the first item.
ii. This is the second item.
iii. This is the third item.
This is a long following
paragraph ...
</pre>
<p>(Note the use of the implicit counter increment.)</p>
</div>
<!-- ====================================================================== -->
<h3 id=content-property><span class=secno>6.1. </span> Generating the
computed value of the ‘<code class=property>content</code>’
property</h3>
<p>If a ‘<code class=css>::marker</code>’ pseudo-element has
its ‘<code class=property>content</code>’ property set to
‘<code class=css>normal</code>’, the computed value of the
marker's ‘<code class=property>content</code>’ property must
be constructed according to the following algorithm:
<ol>
<li>If the computed value of ‘<a href="#list-style-image"><code
class=property>list-style-image</code></a>’ is a valid image, then
the computed value of the ‘<code
class=property>content</code>’ property is the value of the
‘<a href="#list-style-image"><code
class=property>list-style-image</code></a>’ property.
<li>Otherwise, if the computed value of ‘<a
href="#list-style-type"><code
class=property>list-style-type</code></a>’ is a string, then the
computed value of the ‘<code class=property>content</code>’
property is that string.
<li>Otherwise, if the computed value of ‘<a
href="#list-style-type"><code
class=property>list-style-type</code></a>’ is the keyword ‘<a
href="#inline"><code class=css>inline</code></a>’, and the list
item has a child element which is an <i
title=inline-marker-candidate>inline marker candidate</i>, the computed
value of the ‘<code class=property>content</code>’ property
is the textual contents of the list item's first <i
title=inline-marker-candidate>inline marker candidate child</i>.
<li>Otherwise, if the computed value of ‘<a
href="#list-style-type"><code
class=property>list-style-type</code></a>’ is the name of a counter
style, then the computed value of the ‘<code
class=property>content</code>’ property is ‘<code
class=css>counter(list-item, <a
href="#ltcounter-style"><i><counter-style></i></a>)</code>’,
where <a href="#ltcounter-style"><i><counter-style></i></a> is the
computed value of the ‘<a href="#list-style-type"><code
class=property>list-style-type</code></a>’ property, followed by a