"TagOntology is about identifying and formalizing a conceptualization of the activity of tagging, and building technology that commits to the ontology at the semantic level."
H. Kim, A. Passant, J. Breslin, S. Scerri, and S. Decker. Proceedings of the 2nd IEEE International Conference on Semantic Computing, 0, page 315-322. Los Alamitos, CA, USA, IEEE Computer Society, (August 2008)