Browntooth

Derived from the more common 'Bluetooth', Browntooth is a standard communication format used by hobos and/or tramps.

Said vagrant will emit a rambling noise from their mouth indeterminable to anyone not 'Browntooth' compatible. Once the noise is picked up by a fellow rubbish-raider the two can communicate freely.

The tramp used browntooth to locate fellow tramps in the vicinity.