<csstest def="Syntax and parsing of unknown pseudo-classes" module="W3C Selectors" modulename="css3-modsel" number="160" rev="1.0" date="20-november-2001" xmlns="http://www.example.org/css3tests">

<author>Ian Hickson</author>

<cssrules>
  p { background: lime; }
  p:subject { background: red; } /* this is not valid CSS, and if UAs
  implemented the experimental :subject pseudo-class they should have
  used the :-vnd-ident syntax. */
</cssrules>

<code>
 <p xmlns="http://www.w3.org/1999/xhtml">This line should have a green background.</p>
</code>

</csstest>