ISO 13250-2: Topic Maps — Data Model is part 2 of ISO 13250, the topic maps standard, and defines a formal data model for topic maps, which will be used to define the XML topic map syntax (XTM), and also be the foundation for the query language (TMQL) and the schema language (TMCL). It is often known by its acronym: TMDM. (In case you are wondering, yes, it used to be known as the SAM, or Standard Application Model.)
At the moment both TMDM and XTM 2.0 are ISO standards, purchasable from the ISO shop. This means they are both officially finished and stable. Corrections have been made to TMDM since publication; see below for details.
Related links are:
Schema files for XTM 2.0 are also available:
If you have comments or questions related to these specifications, but are not involved in the ISO process, you can send them to the authors: Lars Marius Garshol and Graham Moore.