Wrote this comment to somebody else's blog post at work. Thought I'd cut-n-paste it here:

Tagging is tres-cool, however I'm not sure about this microformat - there are a couple of warts IMO:

  • Not a biggie, but at first glance the format looks like you're tagging the target of the link (at least to me). Reading the spec shows that the URL is actually intended to denote the tag itself (e.g. http://technorati.com/tag/apple)
  • I think the use of a URL to denote the tag implies a stronger semantic meaning than tags can effectively support. I.e. To me it implies: "By 'http://technorati.com/tag/apple' I mean the same as all these people who have tagged their content 'http://technorati.com/tag/apple'" One of the breakthroughs for me with the del.ic.ious tagging was that the semantics of tagging were very loose and local. The tag meant "I'm categorising this content with this tag" - it didn't imply that I mean the same thing as the tag in joeblogg's tagging scheme. Personally I would have preferred a no-url scheme - e.g. <span rel="tag">apple</span>. My guess is that the technorati tags aggregator just lobbs the URL off of the tag anyway.
  • Of course the other thing to note is that you're tagging your own content, so you don't get the same levels of diversity and serendipity as an open tagging system.

(Technorati tag )