Experiments with rel (13th July 2006)
The rel and rev attributes can be used on <link> and <a> elements to indicate a relationships between documents. For example:
<link rel="home" title="W3C" href="/">
<a rel="home" href="/">W3C</a>Both of these are equivalent, each meaning that the document at href is the homepage for the current document. The <a> version is a bit smaller and is visible to all users, while the <link> version is bigger and only visible in devices which implement a special mechanism to display it.
You can read more about how these links are implemented in various browsers and extensions in my Navigation Using rel review.