onfonem

To swear on your friends and family or people you associate with often in gangs mostly used by GDs

A rudimentary type of 19th century telephone, the telephone relied on system of folks and their immediate friends to tension wires at a precise time in order to generate barometric frequencies that would route the users call to the appropriate destination by using a complex series of gears and pulleys.

Fun fact there are only 3 surviving onfonem operators left alive in the world!