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In the ValueSet resource any number of terms ('designations 
') in additional languages and dialects can be specified for a particular concept in a value set definition using the ValueSet.compose.include.concept.designation element. The language is specified as a BCP-47 language code as required by the 'designation.language ' element, with the value taken from the 'languageCode' field of the RF2 Descriptions file ('languageCode' is ISO-639-1, a subset of BCP-47). BCP-47 private use extensions can be used to specify a SNOMED CT language reference set for a term. The format of these extensions is <lang>-x-sctlang-<language reference set ID>, for example en-x-sctlang-90000000-00005090-07 corresponds to the US English language reference set. The SNOMED CT Expression Constraint Language specification also lists a number of aliases for language reference sets which may be used in addition to the private use extensions: ECL specification, Appendix C, Dialect Aliases. The type of the term (e.g., the SNOMED CT code for "Fully specified name", "Synonym" or "Definition") can be specified in 'designation.use '. More details on working with languages while using SNOMED CT and FHIR can be found here: http://snomed.org/fhir-languages
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