description: Specifies whether a particular element or resource is expected to have an id or not. Note that this can be done in a profile on the element, but it is sometimes useful to say this e.g. on an abstract element in a logical model package_name: rs/hl7.fhir.uv.tools derivation: constraint name: IdExpectationExt type: Extension elements: extension: {index: 0} url: pattern: {type: uri, value: 'http://hl7.org/fhir/tools/StructureDefinition/id-expectation'} type: uri index: 1 value: choices: [valueCode] index: 3 valueCode: {type: code, choiceOf: value, index: 4} package_version: 0.4.1 extensions: {} class: extension kind: complex-type url: http://hl7.org/fhir/tools/StructureDefinition/id-expectation base: http://hl7.org/fhir/StructureDefinition/Extension version: 0.4.1 required: [value, valueCode]