description: An extension to support adding a BodyStructure on an Observation. package_name: fhir.r4.ukcore.stu3.currentbuild derivation: constraint name: ExtensionUKCoreObservationBodyStructure type: Extension elements: url: pattern: {type: uri, value: 'http://hl7.org/fhir/5.0/StructureDefinition/extension-Observation.bodyStructure'} type: uri index: 0 value: choices: [valueReference] index: 2 valueReference: type: Reference choiceOf: value refers: ['http://hl7.org/fhir/StructureDefinition/BodyStructure'] index: 3 package_version: 0.0.8-pre-release class: extension kind: complex-type url: http://hl7.org/fhir/5.0/StructureDefinition/extension-Observation.bodyStructure base: http://hl7.org/fhir/StructureDefinition/Extension version: 1.0.0 required: [value, valueReference]