The Real Meanings of Police 10 Codes

In 1937 due to limited communication channels, Charles "Charlie" Hopper, Communications Director for the Illinois State Police, developed the "10 code" for police radio communication.

Hopper's intention was to create something of a shorthand for law enforcement officers and personnel to use on the radio scanner. It was a way to reduce the use of speech on the radio during a time when police radio channels were limited.

The Police 10 Codes spread like wildfire among police departments and officers. They quickly became standard among law enforcement agencies across the United States.

While the meaning of some police scanner codes varies among jurisdictions, most of the more commonly used ones, such as 10-4 and 10-20, are similar across the board.

Law enforcement agencies, in recent years, have started to migrate back to using plain speech. However, many of the Police 10 Codes are still used by more experienced officers.

Here's the list of codes and what each code means:

  • 10-0 Caution
  • 10-1 Unable to copy - change location
  • 10-2 Signal good
  • 10-3 Stop transmitting
  • 10-4 Acknowledgement (OK)
  • 10-5 Relay
  • 10-6 Busy - stand by unless urgent
  • 10-7 Out of service
  • 10-8 In service
  • 10-9 Repeat
  • 10-10 Fight in progress
  • 10-11 Dog case
  • 10-12 Stand by (stop)
  • 10-13 Weather - road report
  • 10-14 Prowler report
  • 10-15 Civil disturbance
  • 10-16 Domestic disturbance
  • 10-17 Meet complainant
  • 10-18 Quickly
  • 10-19 Return to ...
  • 10-20 Location
  • 10-21 Call ... by telephone
  • 10-22 Disregard
  • 10-23 Arrived at scene
  • 10-24 Assignment completed
  • 10-25 Report in person (meet) ...
  • 10-26 Detaining subject, expedite
  • 10-27 Drivers license information
  • 10-28 Vehicle registration information
  • 10-29 Check for wanted
  • 10-30 Unnecessary use of radio
  • 10-31 Crime in progress
  • 10-32 Man with gun
  • 10-33 Emergency
  • 10-34 Riot
  • 10-35 Major crime alert
  • 10-36 Correct time
  • 10-37 (Investigate) suspicious vehicle
  • 10-38 Stopping suspicious vehicle
  • 10-39 Urgent - use light, siren
  • 10-40 Silent run - no light, siren
  • 10-41 Beginning tour of duty
  • 10-42 Ending tour of duty
  • 10-43 Information
  • 10-44 Permission to leave ... for ...
  • 10-45 Animal carcass at ...
  • 10-46 Assist motorist
  • 10-47 Emergency road repairs at ...
  • 10-48 Traffic standard repair at ...
  • 10-49 Traffic light out at ...
  • 10-50 Accident (fatal, personal injury, property damage)
  • 10-51 Wrecker needed
  • 10-52 Ambulance needed
  • 10-53 Road blocked at ...
  • 10-54 Livestock on highway

    10-55 Suspected DUI

  • 10-56 Intoxicated pedestrian
  • 10-57 Hit and run (fatal, personal injury, property damage)
  • 10-58 Direct traffic
  • 10-59 Convoy or escort
  • 10-60 Squad in vicinity
  • 10-61 Isolate self for message
  • 10-62 Reply to message
  • 10-63 Prepare to make written copy
  • 10-64 Message for local delivery
  • 10-65 Net message assignment
  • 10-66 Message cancellation
  • 10-67 Clear for net message
  • 10-68 Dispatch information
  • 10-69 Message received
  • 10-70 Fire
  • 10-71 Advise nature of fire
  • 10-72 Report progress on fire
  • 10-73 Smoke report
  • 10-74 Negative
  • 10-75 In contact with ...
  • 10-76 En route ...
  • 10-77 ETA (estimated time of arrival)
  • 10-78 Need assistance
  • 10-79 Notify coroner
  • 10-80 Chase in progress
  • 10-81 Breathalyzer
  • 10-82 Reserve lodging
  • 10-83 Work school crossing at ...
  • 10-84 If meeting ... advise ETA
  • 10-85 Delayed due to ...
  • 10-86 Officer/operator on duty
  • 10-87 Pick up/distribute checks
  • 10-88 Present telephone number of ...
  • 10-89 Bomb threat
  • 10-90 Bank alarm at ...
  • 10-91 Pick up prisoner/subject
  • 10-92 Improperly parked vehicle
  • 10-93 Blockade
  • 10-94 Drag racing
  • 10-95 Prisoner/subject in custody
  • 10-96 Mental subject
  • 10-97 Check (test) signal
  • 10-98 Prison/jail break
  • 10-99 Wanted/stolen indicated

This list of police radio codes is particularly useful when watching Law and Order: SVU or CSI: Miami.

Lastly, take a tip from Tommy Boy and don't include any 9er's in security language.

Real Customer Reviews

The home security reviews on our site are left by both customers organically looking to share their opinions and customers whose opinions have been solicited.

In order to ensure the legitimacy of reviews on BestHomeSecurityCompanys.com, all reviews are moderated by real people. We check each review for fraud and violation of our review guidelines. Customer reviews are unbiasedly checked and used to rank the home security companies on our site. You can read the breakdown of how we rank companies here.