Taxonomies are essential to the Description part of UDDI. They are identified by tModels and their values are described using KeyedReferences. They are most frequently used as Categorization, Relational and Identification systems.

Registry administrators and users can publish their own taxonomies. Still, dozens of taxonomies come as a part of the BEA AquaLogic Service Registry or are mandated by the UDDI Registry specification.

Familiarizing yourself with the taxonomies available in a particluar registry will lead to more useful and accurate record descriptions. It will also help in understanding which taxonomies to use when searching.