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

If present and true, indicates that the item establishes a different subject for the group in a response.

element_id	types
Extension
Extension.extension
Extension.url
Extension.value[x]	boolean
Extension
Extension.id	http://hl7.org/fhirpath/System.String
Extension.extension	Extension
Extension.url	http://hl7.org/fhirpath/System.String
Extension.value[x]	boolean