Procedure words (abbreviated to prowords) are words or phrases limited to radiotelephony procedure used to facilitate communication by conveying information in a condensed standard verbal format.[1] Prowords are voice versions of the much older procedural signs for Morse code which were first developed in the 1860s for Morse telegraphy, and their meaning is identical.
The NATO communications manual ACP-125[2] contains the most formal and perhaps earliest modern (post-World War II) glossary of prowords, but its definitions have been adopted by many other organizations, including the United Nations Development Programme,[3] the U.S. Coast Guard,[4] US Civil Air Patrol,[5] US Military Auxiliary Radio System,[6] and others.
Prowords are one of several structured parts of radio voice procedures, including brevity codes and plain language radio checks.