Definition of the CIDOC CRM
The current official version of the Definition of the CIDOC CRM is version 5.0.4, released in December 2011 by the CIDOC CRM Special Interest Group (SIG).
Version 3.4.9 (November 2003) was submitted to ISO under the fast-track procedure as an enquiry draft, which resulted in 2006 in the publication of the international standard ISO 21127:2006. The differences between the text published as an ISO standard and version 3.4.9 reside in layout, and in a number of amendments based on comments made by ISO national bodies on the Draft International Standard at the enquiry stage, which were also incorporated in version 4.2 (June 2005) of the CIDOC CRM SIG's reference document.
On December 2014 a new version of the ISO standard became available: ISO21127:2014 (based on version 5.0.4 of the CIDOC CRM). A reference ontology for the interchange of cultural heritage information supersedes ISO 21127:2006. The ISO publication is available in English and French and can be purchased online. The updated standard includes many revisions and corrections and a helpful diagrammatic representation of the ontology.
The Definition of the CIDOC CRM is also available as encodings in the CIDOC-CRM in RDFS, OWL. Users should keep in mind that all such encodings (in the aforementioned languages or any other schema definition language) are implementations of the CIDOC CRM ontology for information systems and contain compromises with the underlying data management mechanisms such as identifier handling and primitive values.