10-4

Government & Politics abbreviation · Police Code

10-4
Stands forAcknowledgment (message received, OK)
CategoriesGovernment & Politics

10-4 stands for Acknowledgment (message received, OK), a police code abbreviation.

Most famous ten-code, meaning "message received and understood" or simply "OK." It is used to confirm instructions over police, trucking and CB radio and has passed into everyday slang.

Example: 10-4, dispatch, I'll head over to the school and check on it.

Usage notes

Ten-codes are generally credited to Charles Hopper, communications director for the Illinois State Police, in the late 1930s, as a way to shorten messages on crowded, noisy radio channels; APCO published and later expanded the list. The 1950s TV show "Highway Patrol" and the 1970s CB radio craze, along with songs such as "Convoy," made "10-4" famous. "10-4, good buddy" became a trucker catchphrase. Because 10-4 is so universal, it is one of the few codes that survives in agencies that have otherwise switched to plain language.

More police code abbreviations

  • 10-29 – Check for wanted
  • 10-3 – Stop transmitting
  • 10-31 – Crime in progress
  • 10-32 – Person with gun
  • 10-33 – Emergency
  • 10-36 – Correct time
  • 10-41 – Beginning tour of duty
  • 10-42 – Ending tour of duty
  • 10-5 – Relay
  • 10-50 – Accident
  • 10-52 – Ambulance needed
  • 10-55 – Intoxicated driver

See all 49 police code abbreviations →