I noticed in a bunch of productions of Rossini's The Barber of Seville, they have Don Basilio (the money grubbing music teacher/wedding planner/rumor monger) dressed like a priest when he's extremely clearly not a man of the cloth. The play does not say anything about him dressing this way, so this is one of those things where it's part of the meta tradition of staging even if it's not actually part of the libretto. well I finally learned why: