<html xmlns="http://www.w3.org/1999/xhtml">
 <head>
  <title>Classes: XHTML global class attribute</title>
  <style type="text/css"><![CDATA[
 p { color: green; }
 .fail { color: red; }
]]></style>
  <link rel="author" title="Ian Hickson" href="mailto:ian@hixie.ch"/>
  <link rel="help" href="https://www.w3.org/TR/css3-selectors/#selectors"/> <!-- bogus link to make sure it gets found -->
  <meta name="flags" content=" namespace" />
 </head>
 <body>
   <p xmlns:xhtml="http://www.w3.org/1999/xhtml">
    <span xhtml:class="fail">This should be green.</span>
   </p>
</body>
</html>