Health informatics — Common terminology services

This standard seeks to establish an international framework for the development of an application programming interface (API) that can be used by messaging software when accessing terminological content. It is not intended to be a complete terminology messaging service in and of itself.

This standard identifies the common functional characteristics that an external terminology must be able to provide. As an example, an HL7-compliant terminology service must be able to determine whether a given concept code is valid within the particular resource. Instead of describing a table keyed by the resource identifier and concept code, the CTS specification describes an application programming interface (API) call that takes a resource identifier and concept code as input and returns a true/false value. Each terminology developer is free to implement this API call in whatever way is most appropriate for them.