CIDOC Conceptual Reference Model

The CIDOC Conceptual Reference Model (CRM) is a formal ontology providing definitions and a formal structure for describing the implicit and explicit concepts and relationships used in cultural heritage documentation. Developed over two decades, it enables researchers, administrators, and the public to integrate and explore complex questions across diverse cultural heritage datasets from museums, libraries, and archives in a software-agnostic manner.

Maintained by the CIDOC CRM Special Interest Group, a volunteer community operating under the International Council of Museums (ICOM), the standard serves as a common language for domain experts and implementers to formulate requirements for information systems. Recognized as an official ISO standard since 2006, it was most recently renewed as ISO 21127:2023, ensuring its continued relevance for semantic interoperability in cultural heritage information systems.