IMO this is a great example of why your idea isnt that great. So the OP would go and define his own link formats, which would then apply to his nodes only. You of course liking the idea would come up with a similar set of links, since youd both be able to do it independently there is a good chance that the two schemes would be different, so now the complexity of link handling by the site and external repeaters goes through the roof.

Seriously im not inclined to saying that i think user requests like this shouldnt happen, but the idea you are referring to just has too many issues for me to agree that its worthwhile.

OTOH i have nothing against allowing for more link types. And for making it easier for users to request new ones. Im just not sure how it should work. I also dont mind allowing for user customization of how the links render to themselves. But of course all of this requires work.