I wanted to make a link between Tantek’s work on XFN and Jon’s experiments in adding semantic information to class attributes of markup.
XFN uses a natural attribute, rel for relationships between the the author and the link target.
Jon’s using the class attribute to add semantic information to the XHTML he stores in a database and searches with XPath. It’s not as natural as rel. But Jon’s trying to add metadata to markup, not just links.
Meanwhile, Buzz wrote a module for Bloxsom which adds the XFN annotation to the links in an entry according to a dictionary you provide.
