description: This cross-version extension represents Specimen.subject from http://hl7.org/fhir/StructureDefinition/Specimen|4.3.0 for use in FHIR R5. package_name: rs/hl7.fhir.uv.xver derivation: constraint name: ext_R4B_Specimen_subject type: Extension elements: url: pattern: {type: uri, value: 'http://hl7.org/fhir/4.3/StructureDefinition/extension-Specimen.subject'} type: uri index: 0 package_version: r4b.r5-0.0.1-snapshot-1 class: extension kind: complex-type url: http://hl7.org/fhir/4.3/StructureDefinition/extension-Specimen.subject base: http://hl7.org/fhir/StructureDefinition/Extension version: 0.0.1-snapshot-1 required: [url]