I'm putting some taxonomical terms in a list, together with a label of "tags", which I think would be best marked up in a definition list. The default output from the CMS (Drupal) is divs, so almost anything would be more meaningful.
But I'm not sure which order it should take. Would you say that "tags" is the definition and the categories are the terms to be defined? This makes more sense to me because "tags" describes the categories; not vice versa.
I might be over-thinking this a bit, but just put it down to curiosity as much as anything.