Don't fuck with the URL format - there's one already established, it should be used (but moreso, it should be damn-well implemented in the client so people stop getting the idea to fuck with it).
What does putting it in a element do that putting it in an anchor won't? Is it for a browser plugin's benefit or what?
mine or his?
steam does what i said, thats were i got the idea from, also magnet links work the same way.