{"code":"effective","description":"Optional Extensions Element","experimental":true,"id":"codesystem-extensions-CodeSystem-effective","name":"effective","resourceType":"SearchParameter","status":"draft","type":"date","url":"http://hl7.org/fhir/SearchParameter/codesystem-extensions-CodeSystem-effective","version":"4.5.0","xpath":"f:CodeSystem/f:extension[@url='http://hl7.org/fhir/StructureDefinition/codesystem-effectiveDate'] | /f:#effectiveDate","xpathUsage":"normal"}