ISO 24633 describes the structure and process for validating a TBX core file and RNG and Schematron schema structures. The following downloads are resources for anyone creating a validation schema. They are a series of UML diagrams that start at low level representation of the TBX core attributes up to a high level data model of a TBX schema. They are downloaded as a PDF file using the following links.
1. Attribute classes: tbx attributeClasses.pdf
2. Elements (excluding children): tbx_elementsCollection.pdf
3. Element entities: tbx_entities.pdf
4. Parent-child relationships in the element entities: tbx_elementsOfEntities.pdf
5. High-level data model: tbx_dataModel_updated.pdf
The UML diagrams used as examples are not the only ones that could be used in creating an RNG schema for TBX Core, but are cited here in order to provide practical orientation.
You can also download a zip file containing generic schemas for TBX core in both RNG and Schematron languages at the the following link.