<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
  "http://www.w3.org/TR/xhtml1/DTD/xhtml1.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en">

<head>
<link rel="alternate stylesheet" media="screen" type="text/css"
  href="outer-sheet.css" title="B"/>
<link rel="stylesheet" media="screen" type="text/css"
    href="outermost-sheet.css" title="A"/>

</head>

<body>
  <ul>
    <li class="outermost">purple</li>
    <li class="outer">blue</li>
    <li class="inner">yellow</li>
  </ul>
</body>
</html>