The Mqual.drift sub-domain governs the detection, measurement, and management of semantic drift within MyHealth@MyHands . the gradual degradation in accuracy of semantic mappings, terminology bindings, and FHIR ConceptMaps that occurs when clinical standards (SNOMED CT, LOINC, ICD, HL7 FHIR profiles) release new versions that retire, revise, or merge concepts previously referenced in active mappings.