Brevity codes are used in amateur radio, maritime, aviation and military communications. The codes are designed to convey complex information with a few words or codes. Some terms are classified to the public.
- RST code - information about the quality of a radio signal being received. Used by amateur radio operators, shortwave listeners. Widespread use by 1912.
- SINPO code - code used to describe the quality of radio transmissions, especially in reception reports written by shortwave listeners.
- Q code - initially developed for commercial radiotelegraph communication, and later adopted by other radio services, especially amateur radio. Used since circa 1909.
Multiservice tactical brevity code
Multiservice tactical brevity codes are codes used by various military forces. The codes' procedure words, a type of voice procedure, are designed to convey complex information with a few words.