XFN (Xhtml Friends Network)

I so vexed anxious with FXN. What actually XFN is? Do this XFN work in Blogger blog machine ? This is a small part of question referring to existence of list of Updates and Bug Fixes for April 18th Blogger machine blog

By trace link given, a brief informasi about XFN is;

XFN™ (XHTML Friends Network) is a simple way to represent human relationships using hyperlinks. In recent years, blogs and blogrolls have become the fastest growing area of the Web. XFN enables web authors to indicate their relationship(s) to the people in their blogrolls simply by adding a 'rel' attribute to their <a href> tags, e.g.:

<a href="http://jeff.example.org" rel="friend met">...

To find out how to write and use XFN, or to write a program to generate or spider it, read the following link:

We can't find any information about this XFN in Blogger Help. Is there someone would tell about this "binongkol" here ?. Since Blogger don't permit profile photo appear in comment box, I think this "binongkol" will be become an opportunity that can eliminate the existing limitation at Blogger comment