Adaptive Blue has released a header/meta tag scheme to simplify semantic tagging of content items. From ReadWriteWeb:
Semantic web company Adaptive Blue has published what it hopes will become a standard for publishers who want to signal in their header tags when a webpage is primarily about a particular book, film, wine or other type of objects … Called AB Meta, the format was developed in concert with a number of other web companies and is aimed to be part of a larger effort to pick up where existing Semantic Web and microformats markup leaves off. It’s simple and extensible.