DLB

DLB OR DEAD LETTER BOX (UK) DEAD DROP (USA)

Information delivery and retrieval technique used by most Intelligence agencies. A DLB may take the form of almost any object from a soda can to a cavity in a brick wall - DLB's are 'loaded' with information on various formats and a signal is left to the intended recipient; anything from chalk marks to a towel hung from a balcony. Useful DLB sites are highly prized and often recconnoitered in advance.