Semantically Interlinked Online Communities - SIOC
A W3C recommendation, SIOC (for Semantically Interlinked Online Communities) is a lightweight ontology for the domain of online communities.
SIOC is a generic ontology with a focus on online communities.
SIOC allows the description of information contained within online community sites (blogs, forums, wikis, ...) and by doing so make it possible to connect these sites together, forming a Social Web of Data. https://www.w3.org/wiki/SIOC/WhatIsSIOC
J.G. Breslin, A. Harth, U. Bojars, S. Decker, "Towards Semantically-Interlinked Online Communities", Proceedings of the 2nd European Semantic Web Conference (ESWC '05), LNCS vol. 3532, pp. 500-514, Heraklion, Greece, 2005.
U. Bojars, J.G. Breslin, A. Passant, "SIOC Browser - Towards a Richer Blog Browsing Experience", The 4th Conference ( Reloaded), Vienna, Austria, October 2006.