The XML based language mvdXML has been developed to define MVDs with IFC. It also has the ability to define allowable values at particular attributes of particular data types.
Various validation formats are already commonplace in the software industry for checking data conformance such as XML Schema Definition (XSD), EXPRESS (ISO 10303-11), Schematron, and validation frameworks within programming languages and tools (e.g. NUnit, JUnit).
Since the original publication of mvdXML 1.0 in 2013 the interest in mvdXML usage has moved beyond simply documenting MVDs to also include validation. The main focus of mvdXML 1.1, beside bug fixing and general improvements, had been in enhancing the validation part. In addition, the documentation and the examples have been improved to ease the understanding of the scope and methodology behind mvdXML. The latest official buildingSMART publication of mvdXML is 1.1.
Documentation for the latest official version of mvdXML (1.1) is available as a PDF, as well as an XSD.
An example of using mvdXML for documentation can be found here. Refer to chapter 7.1 of the PDF documentation.
Future of mvdXML
New technologies and the decision to maintain IFC in UML (XMI) is creating a situation where MVDs are defined in the core of IFC. The Information Delivery Specification (IDS) is the recommended way to define information requirements for IFC datasets.
A group of mvdXML enthousiasts has continued to develop mvdXML in a 1.2 and 1.3 version. These are community versions that have not followed the buildingSMART Process and have not been voted on by the standards committee.