|rel="alternate"| - This is the permalink for the complete entry |rel="about"| - The entry is about this link. |rel="related"| - This link is related to the link the entry is about |rel="via"| = This is the source of the link the entry is about
+1. I also think that 'alternate' and 'about' could be interchangeable (meaning that you can use one or another or both), even though that may introduce a little ambiguity. The point is that many linkblogs don't have an archive to provide permalinks.
-- Anne van Kesteren <http://annevankesteren.nl/>