It was just an example of opening and closing tags vs />. First thing that popped into my head. I can see how it could be confusing. Andf to elaborate as stated about style switching, you would do somethign like:
<link rel="stylesheet" title="Main
CSS" href="foo.
css" media="screen" type="text/
css" />
then
<link rel="alternate stylesheet" title="Alt Main
CSS" href="foo2.
css" media="screen" type="text/
css" />
etc....