http://hl7.org/fhir/uv/sdc/StructureDefinition/sdc-questionnaire-candidateExpression|4.0.0-ballot

A FHIRPath or CQL 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.
typedestination
baseDefinitionhttp://hl7.org/fhir/StructureDefinition/Extension
typehttp://hl7.org/fhir/StructureDefinition/Extension
Extension.value[x].typehttp://hl7.org/fhir/StructureDefinition/Expression