description: This cross-version extension represents ActivityDefinition.subject[x] from http://hl7.org/fhir/StructureDefinition/ActivityDefinition|4.3.0 for use in FHIR R4. package_name: hl7.fhir.uv.xver-r4b.r4 derivation: constraint name: Ext_R4B_ActivityDefinition_subject type: Extension elements: url: base: {max: '1', min: 1, path: Extension.url} pattern: {type: Uri, value: 'http://hl7.org/fhir/4.3/StructureDefinition/extension-ActivityDefinition.subject'} index: 0 value: base: {max: '1', min: 0, path: 'Extension.value[x]'} short: Type of individual the activity definition is intended for choices: [valueCodeableConcept, valueReference, valueCanonical] index: 2 valueCodeableConcept: base: {max: '1', min: 0, path: 'Extension.value[x]'} type: CodeableConcept short: Type of individual the activity definition is intended for choiceOf: value index: 3 valueReference: base: {max: '1', min: 0, path: 'Extension.value[x]'} type: Reference short: Type of individual the activity definition is intended for choiceOf: value index: 4 valueCanonical: base: {max: '1', min: 0, path: 'Extension.value[x]'} type: canonical short: Type of individual the activity definition is intended for choiceOf: value index: 5 package_version: 0.0.1-snapshot-2 class: extension kind: complex-type url: http://hl7.org/fhir/4.3/StructureDefinition/extension-ActivityDefinition.subject base: http://hl7.org/fhir/StructureDefinition/Extension|4.0.1 version: 0.0.1-snapshot-2 required: [url]