http://hl7.org/fhir/StructureDefinition/operationoutcome-authority|5.2.0

A reference to where the rule is defined (based on the authoritative URLs in the applicable conformance resources).
typedestination
baseDefinitionhttp://hl7.org/fhir/StructureDefinition/Extension
typehttp://hl7.org/fhir/StructureDefinition/Extension
Extension.value[x].typehttp://hl7.org/fhir/StructureDefinition/uri