Clarity regarding controlled vocabularies, taxonomies, thesauri, ontologies, and metamodels. With all the scuttlebut going around about folksonomies and tagging, these are important terms to understand. In the process of tagging, it's pretty noticeable
C. Trattner, C. Körner, and D. Helic. Proceedings of the 11th International Conference on Knowledge Management and Knowledge Technologies, page 18:1--18:8. New York, NY, USA, ACM, (2011)
I. Peters, L. Schumann, J. Terliesner, and W. Stock. Heinrich-Heine-University, Heinrich-Heine-University Department of Information Science Universitätsstraße1, 40225 Düsseldorf, Germany, (October 2011)
C. Marlow, M. Naaman, D. Boyd, and M. Davis. HYPERTEXT '06: Proceedings of the seventeenth conference on Hypertext and hypermedia, page 31--40. New York, NY, USA, ACM, (2006)