OMG/HL7 CTS2 Standard

The Object Management Group's Common Terminology Services Version 2 (CTS2) standard defines an accepted industry standard service interface to share, query and maintain value sets and other terminology artifacts. In a nutshell, it is based on a Service Functional Model (SFM) developed by the HL7 community. This specification facilitates the definition of designations and mutual relations of concepts with a common representation.

The main artefacts of CTS2 are

• code systems (and its versions), defined by an “authority”, e.g. by HL7 or even by a small project,
• entities, i.e. concepts, as elements of code systems with an unique code, together with its designations and associations (e.g. is a) between them,
• value sets, i.e. sets of entities, which serve as domains for coded attributes, and
• mappings between code systems.

The CTS2 platform independent model define how code systems, associations, or value sets are organized.