i'm in the happy situation of designing my own site from scratch. which means i can start using all those good practices again, that somehow fell by the wayside on my last website.

so i thought i'd start using rel=tag
i figure the best way to do it is to build it into your website from the beginning, and give your directories the same names as the tag.

but then i started looking at it, and realised that it just doesn't work.

limitation 1: the tag has to be the last word in the url
so
<a rel=tag href="www.example.com/widget">Blah</a>
the word widget is the tag, rather the the word blah

limitation 2: you can't use more than one word as a tag. because it will only allow you to seperate the words with a space or a plus sign
but that means your filename or directory has to have a plus sign or a space in it. And who does that these days?
you could get around it by putting the word on the end of a query string, but they don't allow that either.
if you put
<a rel=tag href="www.example.com/widget?x=blah">Blah</a>
then they still count the word 'widget' as the tag.
(that actually goes against how WordPress implement it as well)

it seems like the whole thing has been designed to make it as difficult as possible for people to use.