What is meant by the rel=“bookmark” link attribute?

Question

What is the purpose of the rel=\"bookmark\" attribute in tags? For example:

Answer 1

The attribute "rel" means relationship. It's a microformats. The HTML4 spec describes a bookmark as "a link to a key entry point within an extended document". By convention (citation needed), this entry point also captures the notion of a "permalink". Exemple:

A Document Entry

Another exemple of rel attribute for tags:

tech

http://microformats.org/wiki/rel-bookmark#rel.3D.22bookmark.22