{"resourceType":"SearchParameter","id":"NamingSystem-period","extension":[{"url":"http://hl7.org/fhir/StructureDefinition/structuredefinition-standards-status","valueCode":"trial-use"}],"url":"http://hl7.org/fhir/SearchParameter/NamingSystem-period","version":"4.0.1","name":"period","status":"draft","experimental":false,"date":"2021-01-17T07:06:13+11:00","publisher":"Health Level Seven International (FHIR Infrastructure)","contact":[{"telecom":[{"system":"url","value":"http://hl7.org/fhir"}]},{"telecom":[{"system":"url","value":"http://www.hl7.org/Special/committees/fiwg/index.cfm"}]}],"description":"When is identifier valid?","code":"period","base":["NamingSystem"],"type":"date","expression":"NamingSystem.uniqueId.period","xpath":"f:NamingSystem/f:uniqueId/f:period","xpathUsage":"normal","comparator":["eq","ne","gt","ge","lt","le","sa","eb","ap"]}