Signal arrow

Signal arrows were arrows that were primarily made and used by wood elves to provide signals for battlefield communications.

Description
Elven fletchers carved these arrows to produce a birdcall-like signal when launched, with different designs imitating different sounds. These were used to stealthily and confidentially relay information on the battlefield, with only the canniest and wisest survivalists able to discern the arrow's imitation from the real thing. Because of the structural compromises made to produce the sound in flight, the arrow was significantly less accurate than their less elaborate quivermates.