#revcanonical

"That’s because while I was watching the kids rolling down the grass slope on top of Parliament House, rev="canonical" started to gain some serious momentum, billing itself as a way to shorten URLs that “doesn’t hurt the Internet.” In my opinion, this is an interesting idea with an very unfortunate execution that’s bad for the Web, and I’m going to enumerate the reasons here. "

"RevCanonical is url shortening with a twist. Instead of creating its own super short versions of links, it checks to see if the link owner has published a shortened version of the given page using HTML link element. If not, we just return the original URL. And you should bug the link owner about providing a better alternative."