http://hl7.org/fhir/StructureDefinition/flag-detail|4.0.1

Points to the Observation, AllergyIntolerance or other record that provides additional supporting information about this flag.

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