GRDDL - bringing more semantic into the WWW and getting it out again
The W3C published a recommendation for the Gleaning Resource Descriptions from Dialects of Languages (GRDDL). The motivation is to make the extraction of semantic data from XML especially from XTHML easier and stimulate by this the usage of embedded sementic data. It describes for example how to extract RDF data from XHTML files that contain data wrapped in a microformat. If you are interested the primer is a good starting point.