A step into Semantic Web - XFN

I just drop by few blogs and wondered what does XFN attribute is for. Curious about the unknown XHTML attribute that I'm really sure I've used well, I tried searching and found XNF site, that is relating websites. How to use it is as simple like this:


1. First, if you have a link (anchor), just add an attribute "rel on it.
2. The value of attributes are as follows (reference: http://gmpg.org/xfn/join)

<a href="http://mypartnersite.com/" rel="acquantance met co-worker">text for my co-worker site</a>

XFN quick reference

relationship category	XFN values
friendship (at most one):	friend acquaintance contact
physical:	met
professional:	co-worker colleague
geographical (at most one):	co-resident neighbor
family (at most one):	child parent sibling spouse kin
romantic:	muse crush date sweetheart
identity:	me

3. Then, at your head tag, you must reference the XFN profile by adding an attribute "profile" and giving it a value of "http://gmpg.org/xfn/11" . and that's it. 
< head profile="http://gmpg.org/xfn/11" >





I'm just thinking that doing this will improve the Web 3.0 - Semantic Web, since it will have something to check whether sites are in what way related or not. That, I'll have to find out and see what happen next. ^_^