description: Specifies whether the related artifact is defining a primary citation for the artifact (i.e. one that should appear in the narrative for the artifact specification. package_name: hl7.fhir.uv.extensions.r4b derivation: constraint name: IsPrimaryCitation type: Extension elements: url: type: uri pattern: {type: Uri, value: 'http://hl7.org/fhir/StructureDefinition/cqf-isPrimaryCitation'} index: 0 value: choices: [valueBoolean] index: 2 valueBoolean: {type: boolean, choiceOf: value, index: 3} package_version: 5.3.0-ballot-tc1 class: extension kind: complex-type url: http://hl7.org/fhir/StructureDefinition/cqf-isPrimaryCitation base: http://hl7.org/fhir/StructureDefinition/Extension version: 5.3.0-ballot-tc1 required: [value, valueBoolean]