Topic Map Constraint Language (TMCL) will provide a means to express constraints on classes of topic maps conforming to ISO/IEC 13250:2000; these will be over and above the constraints currently defined by the Standard Application Model (Data Model for Topic Maps). Its goal will be to provide a language such that a topic map can be said to be conforming within a topic map or within a class of topic maps. It may help optimization both of topic map storage and of TMQL queries based on schema information. It may aid applications in providing more intuitive user interfaces for creating and maintaining topic maps.

This document will define the requirements that we expect the language will provide.

TMCL shall be specified in terms of SAM (Standard Application Model for Topic Maps), a data model, and will not be specified on any serialization format for topic maps. This will automatically allow it to support both XTM and HyTM as well as LTM and AsTMa=, since these all have mappings to SAM.

TMCL is to be developed by ISO/JTC SC34 WG3 and this requirements document is for members of the committee and implementors who have expressed an interest in the development of a Topic Map Constraint Language.