css/css-namespaces/syntax-001.xml

<html xmlns="http://www.w3.org/1999/xhtml">
 <head>
  <link rel="author" title="Anne van Kesteren" href="http://annevankesteren.nl/"/>
  <link rel="author" title="Opera Software ASA" href="http://opera.com/"/>
  <link rel="help" href="http://www.w3.org/TR/css-namespaces-3/#syntax"/>
  <link rel="match" href="reference/ref-lime-1-block.xml"/>
  <title>CSS Namespaces Test Suite: @namespace case-insensitivity</title>
  <style>
   @NAmespace x "http://www.w3.org/1999/xhtml";
   x|p { background: lime }
  </style>
 </head>
 <body>
  <p>This sentence should have a green background.</p>
 </body>
</html>