{description: Code for the event this message represents or link to event definition, package_name: hl7.fhir.r5.core, name: event, type: token, package_version: 5.0.0-snapshot1, class: unknown, kind: null, url: 'http://hl7.org/fhir/SearchParameter/MessageHeader-event', version: 5.0.0-snapshot1}