This is a basic template for understanding 10 codes and signals used by California law enforcement agencies. It’s important to note that these codes can differ from county to county, and not all counties share this specific information publicly.

Understanding 10-codes

10-codes, also known as ten signals, are numerical codes commonly used in law enforcement and emergency services communication. They were originally developed to standardize messages in radio communication, particularly during the 1930s when police radio channels were limited.

The codes are meant to represent common phrases and responses, thereby improving the clarity and speed of communication. For instance, “10-4” is widely recognized as an affirmation, meaning “acknowledged” or “understood.” Other examples include “10-20” to request or provide a location, or “10-71” often signifying a request for an ambulance.

However, it’s crucial to note that these codes can vary significantly between different regions and departments. Some agencies may not use them at all, or may have completely different meanings assigned to the same codes. For this reason, the use of plain language has been encouraged in many areas to avoid any potential confusion.

Despite their varying usage, 10-codes continue to be a key part of communication in many emergency response contexts.

10 Codes

10-1 Receiving Poorly

10-2 Receiving Well

10-3  Stop Transmitting

10-4 O.K.

10-5 Relay to ________

10-6 Busy

10-7 Out of Service

10-8 In Service

10-9 Repeat

10-10 Out of Service, Subject to call

10-12 Visitor or With a Person

10-13 Weather and Road Conditions

10-14 Escort

10-14B Baker Act Transport

10-15 Prisoner in custody

10-16 Pick up Prisoner at ______

10-17 Conduct Investigation

10-19 Return to Station

10-19A Fuel Vehicle

10-19B Court

10-20 Location

10-21 Phone Station

10-22 Disregard

10-23 Stand By

10-24 Trouble, Send Help, Officer Down

10-25 In Contact With

10-26 Message Received

10-27 Drivers License Check

10-28 Check Registration

10-29 FCIC/NCIC Check

10-29P Person Check

10-30 Against Rules

10-31 In Pursuit

10-32 Breathalyzer Available/Operator

10-33 Emergency Message

10-36 Correct Time

10-37 Operator on Duty/Employee

10-39 Message Delivered

10-40 Case Number and Time

10-42 Home/Residence

10-45 Phone at ______

10-46 Urgent

10-48 End of message, Did you copy?

10-49 Wanted Person/Warrant

10-49A Civil Papers Served

10-50 Traffic Stop

10-50F Attempted Traffic Stop with Flee

10-51 Enroute

10-52 E.T.A.

10-53 Coming to your Office

10-54 Negative

10-56 Meet at _______

10-60 Check Tower Lights

10-62 Change to Channel __

10-65 Can you copy?

10-66 Cancel

10-68 Legal Advice

10-71 Send Ambulance

10-75 Off Duty, In Dept Vehicle

10-81 Send Wrecker

10-88 What phone number can you be reached at?

10-96 Unable to Locate

10-97 Arrived

10-98 Completed Call

10-99 Unable to Read

Codes

Code 1 Routine Response

Code 2 Expedite

Code 3 Respond Lights and Siren

Code 4 Cancel Responding Units

Signals

S0 Armed or Caution

S1 DUI; Alcohol or Drugs

S2 Intoxicated Person

S3 Hit and Run

S3F Hit and Run with Injuries

S4 Vehicle Accident

S4F Vehicle Accident with Injuries

S5 Murder

S6 Escaped Prisoner

S7 Dead Person

S8 Missing Person

S8R Recovered Missing Person

S9 Stolen License Plate

S9A Lost License Plate

S10 Stolen Vehicle

S10IP Stolen Vehicle in Progress

S10R Stolen Vehicle Recovery

S11 Abandoned Vehicle

S11P Private Tow

S12 Reckless Driver

S13 Suspicious Vehicle

S13A Suspicious Incident

S13P Suspicious Person

S13X Suspicious Package

S14 Information

S14I Clermont Intelligence Report

S15 Special Detail

S15M Special Detail: Marine

S15R Special Detail: Rainbow

S16 Road Obstruction

S17 Attempt to Locate

S17A Welfare Check

S20 Mentally Ill Person

S20H Homicidal

S21 Burglary

S21A Burglary of Business

S21A IP Burglary of Business in Progress

S21B Burglary of Residence

S21B IP Burglary of Residence in Progress

S22 Verbal Disturbance

S22 IP Verbal Disturbance in Progress

S22 S0 Disturbance with a Weapon

S23 Pedestrian/Hitchhiker

S24 Robbery

S24A Purse Snatch

S24 S0 Armed Robbery

S25 Fire

S25A Structure Fire

S25B Brush Fire

S25C Car Fire

S25F Multiple Dwelling Fire

S25H Commercial Fire

S25X Explosives Problem

S26 Drowning

S27 Trespasser

S28 Riot

S28A Civil Disturbance

S29 Reckless Boat

S30 Bomb Threat

S31 Narcotics

S32 Fraud

S32A Worthless Check

S33 Assault and Battery

S33IP Assault and Battery in Progress

S33 S0 Assault and Battery with a Weapon

S34 Rape

S34A Sex Offense

S34B Verify Sex Predator

S34BAV Sex Offender/Predator Address Verification

S35 Car Burglary

S36 Shooting

S36A Person Shot

S36B Shooting in the Area

S36C Weapons Complaint

S87A Found Person

S88 Noise Complaint

S88F Noise Complaint; Fireworks

S88G Large Gathering

S90 Animal Complaint

S90A Animal Bite

S92 Sick Person

S92A Injured Person

S22 S0 Disturbance with a Weapon

S23 Pedestrian/Hitchhiker

S24 Robbery

S24A Purse Snatch

S97 Boat Accident

S97A Other Boat Emergency

S98 Dangerous Street Condition

S99 Property Check

S99T Traffic Enforcement

S99M Ag/Marine Patrol

S100 Radio Test

S37 Suicide

S37A Suicide Attempt

S37T Suicidal Thoughts

S38 Gambling

S39 Juvenile Complaint

S39A Austistic Juvenile

S39T Juvenile Tobacco Problem

S40 Vandalism

S40A Vandalism of City/County Property

S41 Obscene Phone Call

S41A Threatening Phone Call

S41S Threat at School

S42 Civil Complaint

S42A Solicitor Complaint

S43 Theft/Larceny

S43C Shoplifter

S43C IP Shoplifter in Progress

S44 Abduction

S44A Hostage

S44B Attempted Abduction

S49 Partner

S49A Pick up Partner at ______

S53 Control Burn

S81 Burglar Alarm

S82 Fire Alarm

S83 Miscellaneous

S83A Abandoned 911

S83M Miscellaneous; Ag/Marine

S83R Repo

S86 Lost Property

S86A Found Property

S87 Lost Person

Natures

ACO Animal Complaint (S90)

AOA Other Agency Assistance

COP Citizen on Patrol

COPPS Clermont COPPS Activity

DAV Disabled Vehicle

DCF Dept of Children and Families

⚠️ Please be aware that the provided list of 10 codes and signals is a generic template. Therefore, when listening to any specific county’s law enforcement scanner, please keep in mind that these codes may not align entirely with the county’s specific set. Always use caution and respect privacy when listening to police scanners.