Z codes were intended for military use.

Military teletype: Z codes used as routers in message header.

The old C&W Z Codes are not widely used today.

Z codes are used by NATO countries in military radio communications.

You should use this section to determine whether the X or the Z code is appropriate based on the location of the insured party/ies.

Military shipboard signal lamp: Q codes and Z codes.

ACP-131 is the controlling publication for the listing of Q codes and Z codes.

Military radio continuous wave (CW): Q codes and Z codes.

Where it is not possible to determine whether the X or Z code is appropriate using the guidelines in this section, then specific transactions may be coded M.

Many military and other organizations that use Morse code have adopted additional codes, including the Z code used by most European and NATO countries.

The Z code adds commands and questions adapted for military radio transmissions, for example, "ZBW 2", which means "change to backup frequency number 2", and "ZNB abc", which means "my checksum is abc, what is yours?"

Several other three-letter marks were not issued through oversight or because they were deemed offensive, and the single-letter Z code was left out of this format as a serial letter would have created a duplicate of an existing two-letter code, particularly one used in Northern Ireland.

The use of Q codes and Z codes was not intended for use on voice circuits, where plain language was speedy and easily recognizable, especially when employing the character recognition system in use at the time, such as ALFA, BRAVO, CHARLIE, etc.