IHTSDO is pleased to announce that a revised "SNOMED CT Compositional Grammar Specification and Guide" has been published to the SNOMED CT Document Library.

SNOMED CT Compositional Grammar is a lightweight syntax for the representation of SNOMED CT expressions, which has proven to be both human readable and machine parsable. The use of SNOMED CT expressions in Electronic Health Records (EHRs) provides a standardized way to represent clinical meanings captured by clinicians and enables the automatic interpretation of this meaning. SNOMED CT expressions are also carried in messages, used to define pre-coordinated concepts and used to represent associations between SNOMED CT and LOINC (Logical Observation Identifiers Names and Codes).

The revised SNOMED CT Compositional Grammar Specification and Guide describes a revision to the previously adopted IHTSDO standard. The new specification is completely backwardly compatible with the prior standard, and includes two significant enhancements: Concrete values are now permitted as attribute values, and a definition status may now (optionally) be included at the start of an expression to indicate whether the clinical idea being expressed is 'equivalent to' or a 'subtype of' the expression. The new Specification and Guide defines the formal syntax of SNOMED CT Compositional Grammar, explains a set of example expressions and provides guidance to assist in the implementation of this syntax.

Click here for a direct link to the "SNOMED CT Compositional Grammar Specification and Guide."