Here's another useful RDF vocabulary: SIOC, Semantically-Interlinked Online Communities:
SIOC (Semantically Interlinked Online Communities) is an ontology for describing discussion forums and posts on topic threads in online community sites. This includes but is not limited to: blogs, bulletin boards, mailing lists, newsgroups, etc.
My major issue with SIOC is that it's working in the same knowledge space as Atom N3 (previously mentioned here) but uses a different vocabulary. Obviously, RDF knows how to work around this but it's a shame that SIOC didn't use Atom's painstakingly thought out terminology. I suspect this happened because SIOC comes more from the Bulletin Board world than the Blogging one.
