Linking in XHTML 2.0
http://www.ibm.com/developerworks/xml/library/x-xhtmlnk.html

Dubinko, Micah
IBM
2005

Abstract:

As a fundamental part of the Web, hypertext linking has been the subject of repeated attempts at standardization beyond the basic format allowed in simple HTML. Such attempts can be characterized as efforts to balance machine processing ability with authoring convenience. The latest specification in this area, XHTML 2.0, just might have gotten it right.