http://hl7.org/fhir/StructureDefinition/questionnaire-referenceProfile|5.2.0

Where the type for a question is \"Reference\", indicates a profile that the resource instances pointed to in answers to this question must be valid against.
element_idtypes
Extension
Extension.extension
Extension.url
Extension.value[x]
Extension
Extension.id
Extension.extension
Extension.url
Extension.value[x]