About: Relator (law)

Relator /rɪˈleɪtər/, female relatrix /rɪˈleɪtrɪks/, (Latin for "narrator") is the legal term meaning a private person at whose relation or on whose behalf an application for a quo warranto or mandamus is filed. The relator appears as one beneficially interested, but the action is maintained on his behalf. The relator furnishes the knowledge or facts on which an information or a proceeding in quo warranto is based. Such a proceeding is usually in the name of the state, ex rel. (ex relatione = "[arising] out of the narration") of the relator, and so is called an "ex rel. action".