description: Flag denoting whether parent item is preferred - e.g., a preferred address or telephone number. package_name: rs/hl7.fhir.core derivation: constraint name: preferred type: null elements: extension: {name: extension, index: 0} url: type: uri pattern: {type: uri, value: 'http://hl7.org/fhir/StructureDefinition/iso21090-preferred'} index: 1 value: choices: [valueBoolean] index: 3 valueBoolean: {type: boolean, choiceOf: value, index: 4} package_version: 1.4.0 extensions: {} class: datatype kind: datatype url: http://hl7.org/fhir/StructureDefinition/iso21090-preferred base: http://hl7.org/fhir/StructureDefinition/Extension version: null required: [value, valueBoolean]