http://hl7.org/fhir/StructureDefinition/capabilitystatement-supported-system|4.0.1

A code system that is supported by the system that is not defined in a value set resource.

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