UK SNOMED CT and dm+d

It is not currently possible to validaste UK terminology using HL7 Validation. The HL7 Validator will by default validate against international SNOMED CT. This validation can be disabled by via the -tx n/a parameter.

It is recommmended to directly use the NHS Digital Terminology Server to validate UK SNOMED and dm+d coding. This is FHIR R4 terminology server which contains UK SNOMED and dm+d CodeSystem. It supports terminology operations such as $validate-code which allows a SNOMED CT code to be checked against a `FHIR (SNOMED) ValueSet.