Domofon is the Russian word for the doorphone system found outside most apartment blocks in Russia and neighbouring countries, where a visitor buzzes a flat and the resident answers before unlocking the door. The short electronic buzz has become a familiar shorthand online for arrivals, uninvited guests and pranks, circulating on soundboards and in short videos rather than coming from a single film or song. Its staying power comes from how instantly recognisable it is to anyone who has waited for a buzzer to be answered.