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The SNOMED CT Machine Readable Concept Model (MRCM) represents the SNOMED CT concept model rules in a form that can be read and tested by a computer. A human readable version of the SNOMED CT concept model can be found in the SNOMED CT Editorial Guide (, along with additional guidance for SNOMED CT authors. A computable version of the MRCM is published as a set of reference sets in the SNOMED CT international edition, and can be browsed via the MRCM browser.

This specification defines the format used by SNOMED International's MRCM. This format uses the SNOMED CT Reference Set mechanism to provide a file structure with inbuilt versioning, and the Expression Constraint Language to represent intensional SNOMED CT subsets referred to by the concept model rules. This allows distribution of the MRCM using standard RF2 reference set files and interpretation of the rules using tools that support the SNOMED CT Expression Constraint Language.

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