Roman candle aid to navigation alarm amber light balefire beacon beacon fire bell bell buoy blinker blue peter buoy calumet caution light downing of arms empty hands flag of truce flare fog bell fog signal fog whistle foghorn glance go light gong buoy green light hand of friendship heliograph high sign international alphabet flag international numeral pennant kick leer marker beacon nod nudge offer of parley olive branch outstretched hand parachute flare parley peace feelers peace offer peace offering peace pipe pilot flag pipe of peace poke police whistle propitiatory gift quarantine flag radio beacon red flag red light rocket sailing aid semaphore semaphore flag semaphore telegraph sign signal signal beacon signal bell signal fire signal flag signal gong signal gun signal lamp signal light signal mast signal post signal rocket signal shot signal siren signal tower spar buoy stop light the nod the wink touch traffic light traffic signal truce flag watch fire wigwag wigwag flag wink yellow flag