+ | MQName -> key "name"
+ | MQTheory -> key "theory"
+ | MQTitle -> key "title"
+ | MQContributor -> key "contributor"
+ | MQCreator -> key "creator"
+ | MQPublisher -> key "publisher"
+ | MQSubject -> key "subject"
+ | MQDescription -> key "description"
+ | MQDate -> key "date"
+ | MQType -> key "type"
+ | MQFormat -> key "format"
+ | MQIdentifier -> key "identifier"
+ | MQLanguage -> key "language"
+ | MQRelation -> key "relation"
+ | MQSource -> key "source"
+ | MQCoverage -> key "coverage"
+ | MQRights -> key "rights"
+ | MQInstitution -> key "institution"
+ | MQContact -> key "contact"
+ | MQFirstVersion -> key "firstversion"
+ | MQModified -> key "modified"