Voice procedure includes various techniques used to clarify, simplify, and standardize spoken communications over two-way radios, in use by the military, in civil aviation, police and fire dispatching systems, citizens' band radio (CB), etc. Voice procedure communications are intended to maximize clarity of spoken communication and reduce misunderstanding. It consists of signalling protocol such as the use of abbreviated codes like the CB radio ten-code, Q codes in amateur radio and aviation, police codes, etc., and jargon. For instance the United States Air Force uses the term "Check Rog" meaning received and acknowledged. Some elements of voice procedure are understood across many applications, but significant variations exist. The military of the NATO countries have similar procedures in order to make cooperation easier, and pseudo-military organizations often base their procedures on them, so some commonality exists there.