description: A FHIRPath expression or FHIR Query that resolves to a list of candidate answers for the question item or that establishes context for a group item. The user may select from among the candidates to choose answers for the question. package_name: hl7.fhir.uv.sdc derivation: constraint name: CandidateExpressionExtension type: Extension elements: url: type: uri pattern: {type: Uri, value: 'http://hl7.org/fhir/uv/sdc/StructureDefinition/sdc-questionnaire-candidateExpression'} index: 0 valueExpression: {type: Expression, index: 1} package_version: 2.7.0 class: extension kind: complex-type url: http://hl7.org/fhir/uv/sdc/StructureDefinition/sdc-questionnaire-candidateExpression base: http://hl7.org/fhir/StructureDefinition/Extension version: 2.7.0