The Citation Typing Ontology (CiTO) is an ontology, written in OWL 2 DL, to enable characterization of the nature or type of citations, both factually and rhetorically, and to permit these descriptions to be published on the Web.
S. Aya, C. Lagoze, und T. Joachims. Proceedings of the International Conference on Knowledge Management, Seite 287--298. World Scientific Publishing, (Oktober 2005)