<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01//EN"> <html> <head> <title>Syntax and parsing of unknown psuedo-classes</title> <style type="text/css"> 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. */ </style> <link rel="first" href="css3-modsel-1.html" title="Groups of selectors"> <link rel="prev" href="css3-modsel-159.html" title="Syntax and parsing of new pseudo-elements"> <link rel="next" href="css3-modsel-161.html" title="Syntax and parsing of unknown psuedo-classes and pseudo-elements"> <link rel="last" href="css3-modsel-d5e.html" title="NEGATED :indeterminate with :checked"> <link rel="up" href="./index.html"> <link rel="top" href="../../index.html"> </head> <body> <p>This line should have a green background.</p> </body> </html>