I’ve just updated my weblog categories today, and came across the usual problems (e.g. splitting a category like Audio into Music and Radio means tags on previous posts have to be checked to make sure they are still correct). It’s not easy, and of course everyone has their own ideas about what structure a category hierarchy should have. John McCormac is using Technorati tags which seems like a good idea, so I might install one of the tags modules for WordPress. And there’s also the option of using the SKOS framework. For now, I’ve changed the description of each category to be an ODP URL.