RDFa, Microdata, and RDF (Two Notes Published by the W3C HTML Data Task Force) The HTML Data Task Force of the Semantic Web Interest Group has published two Notes today: The HTML Data Guide aims to help publishers and consumers of HTML data. With several syntaxes (microformats, microdata, RDFa) and vocabularies (schema.org, Dublin Core, microformat vocabularies, etc.) to choose from, it provides g