css3-values/attr.html

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title>Initial</title>
<style type="text/css">
ol li {border: 1px dotted gray;}
li::before {content: "[" attr(class) "] <" attr(id) "> ";}
li[maxlength] {
	width: attr(maxlength em);
}
li[data-length] {
	width: attr(data-length px);
}
</style>
</head>
<body>

<ol>
<li class="item">A list item.</li>
<li class="item" id="li02">A list item.</li>
<li class="item" maxlength="5">A list item.</li>
<li class="item" data-length="100">A list item.</li>
</ol>

</div>

<a href="http://www.w3.org/TR/css3-values">Specification</a>

</body>
</html>