Ten-code

Ten-codes, properly known as ten signals, are code words used to represent common phrases in voice communication, particularly in radio transmissions. The codes, developed in 1937 and expanded in 1974 by the Association of Public Safety Communication Officials (APCO), allow for brevity and standardization of message traffic. They have historically been widely used by law enforcement officers in North America, although the trend is away from their use in recent years with more departments discouraging the use of ten-codes and encouraging "clear" or plain language communications.

While "ten codes" were intended to be a terse, concise, and standardized system, the proliferation of different meanings has rendered it useless for situations where people from different agencies and jurisdictions need to communicate. For this reason its use is expressly forbidden in the Incident Command System.

Some organizations and municipalities also use other codes in addition to the ten-codes. An example is the California Highway Patrol's use of eleven-codes.

Historic overview

Ten-codes were developed in the 1940s at a time when police radio channels were limited, to reduce use of speech on the radio. Credit to the originator goes to Charles Hopper. He was the Communications Director at the Illinois State Police, District 10, located in Urbana, Illinois. "Charlie" was involved in radio for many years and saw a need for a short cut for radio transmission on the State Police airways. Ten-codes were later adapted for use by CB radio enthusiasts before its pop culture explosion in the late 1970s; thus, many of the phrases, such as 10-4 and "what's your twenty", have entered everyday use in the English language. Popular fictional accounts of ten-codes in use among CB-communicating truckers may be heard in the 1975 Convoy song by C.W. McCall, and the 1978 movie Convoy.

In the fall of 2005, responding to inter-organisational communication problems during the rescue operations after Hurricane Katrina, the United States Federal Emergency Management Agency (FEMA) discouraged the use of ten-codes and other codes due to their high variability in meaning (see the November 2005 articles in External links, below). The Department of Homeland Security reportedly has plans to do away with 10-code use as well, in favor of "Plain English".

List of ten-codes

The following list, given in ascending order and grouped by decade, illustrates the current usage of various ten-codes. Only a handful of them are standardized. Some are fairly consistent, while others (such as 10-40) can have completely different meanings, many of which are not listed here.

Presentation:

• Multiple meanings for the same code are in a bulleted list
• The first bold definition is the current APCO specification.
• Popular alternate meanings follow in bold.
• Less common meanings are in regular typeface
• Meanings specific to CB radio are set in italics.

10-0s

Code	Meaning(s)
10-00	Officer Down (Ten-Double Zero)
10-0	Caution
10-1	Poor Reception Officer Needs Help Unable to Copy
10-2	Good Reception Signal Good OK For Now, Continue With Status Checks
10-3	Stop Transmitting Ok, No Further Status Checks Needed
10-4	Message Received Affirmative Ok Understood
10-5	Pick up an item Relay
10-6	Busy Out At Call
10-7	Out of Service Ending tour of Duty
10-8	Back In Service On Duty Available for next Call
10-9	Repeat

10-10s

Code	Meaning(s)
10-10	Fight In Progress out of service, off duty Permission to go on common channel (car to car transmission, rather than through dispatch) negative transmission completed welfare check Other non-Criminal Event On Break, Subject To Calls
10-11	Animal Problem road-side check talking too fast alarm call en route
10-12	Standby visitors present disregard call in reports at scene check revocation
10-13	Advise Weather/Road Conditions Officer in need of assistance
10-14	Suspicious Person/Report of Prowler convoy or escort
10-15	Civil Disturbance prisoner/suspect in custody Check if Vehicle Stolen - People in or out rolling/stationary vehicle.
10-16	Domestic Disturbance make pickup at ___ Vehicle Stolen
10-17	Meet Complainant pick up papers at ___ urgent business Vehicle Not Stolen En Route
10-18	Urgent complete assignment ASAP anything for us? drunk
10-19	Return to ______ Returning from Scene Return/EnRoute To Station

10-20s

Code	Meaning(s)
10-20	Specify Location/My Location is ___
10-21	Please Call ___ Phone Call
10-22	Disregard report to ___ send blood technician
10-23	Arrived at Location/On Scene stand by on this frequency status check en route to call sex offense
10-24	Assignment Completed trouble at station unit not available direct traffic
10-25	Report to ___ Please Contact ___ Officer Needs Help
10-26	Detaining Suspect (implying "Please expedite") check auto registration ETA ___ disregard last info phone residence
10-27	Request Drivers License Check Vehicle Registration Request I am moving to channel ___
10-28	Request Vehicle Registration Check driver's license request identify your station missing person
10-29	Request Arrests/Warrants Check time is up for contact Stolen Vehicle

10-30s

Code	Meaning(s)
10-30	unauthorized use of radio danger/caution special check at ___ juvenile robbery in progress (New York City)
10-31	crime in progress domestic disturbance check for local warrants suspicious person
10-32	person with gun fight in progress radio check check NCIC DWI test
10-33	emergency, all units stand by officer needs help disturbance at ___ fire
10-34	riot frequency open (cancels 10-33) help needed trouble at jail correct time meet officer
10-35	major crime alert confidential information suspicious person
10-36	correct time of day? Confidential information
10-37	suspicious vehicle identify yourself wrecker needed at ___ shoplifter time of day?
10-38	stopping suspicious vehicle Traffic Stop ambulance needed station report satisfactory phone communications vandalism
10-39	run with lights & siren your message was delivered Backing Up____ false alarm, premises were occupied contact officer disturbance

10-40s

Code	Meaning(s)
10-40	run silent (no lights & siren) false alarm, no activity, premises appears secure please tune to channel ___ expedite advise if available suspicious person dead animal mental patient lunch fight shots fired
10-41	begin duty radio test intoxicated person debris in street neighbor trouble
10-42	end duty traffic accident at ___ malicious mischief request dispatch times
10-43	information traffic jam at ___ request criminal history pick up passenger armed robbery rescue call
10-44	permission to leave patrol I have a message for you transmission received rape possible mental subject traffic accident (no injury)
10-45	animal carcass pick up officer fatality Drivers License/Warrant Check fire alarm fueling vehicle all units in range please report coffee break traffic accident (injury) non-injury accident (Kentucky)
10-46	motorist assist motor vehicle accident (MVA) lunch break fuel break wrecker injury accident (Kentucky)
10-47	emergency road repair disorders and family trouble call home missing person drunk driver blood run license plate check (Kentucky)
10-48	traffic control request criminal history runaway juvenile use caution
10-49	traffic light out EMERGENCY, clear air en route to assignment bathroom break any traffic serving warrant

10-50s

Code	Meaning(s)
10-50	accident Often referred to as a 10-50 PD (Property Damage), a 10-50 PI (Personal Injury), or (rarely) 10-50 F (Fire or Fatality) no messages break channel auto accident with property damage
10-51	wrecker needed auto accident with injuries phone message
10-52	ambulance needed Accident with Injuries fatal auto accident message for assignment alarm
10-53	road blocked silent alarm
10-54	animals on highway Fatal Accident silent pursuit car stop
10-55	intoxicated driver or DWI security check ambulance call
10-56	intoxicated pedestrian Intoxicated Driver warrant indicated arrived at scene
10-57	hit & run accident Intoxicated Person narcotics officer at pistol range
10-58	direct traffic wrecker DOA teleprinter message
10-59	escort or convoy out of car checking violation ambulance bomb threat

10-60s

Code	Meaning(s)
10-60	squad in vicinity traffic stop subject negative what is next message number? coffee break assist motorist major emergency canceled
10-61	personnel in vicinity subject has record - not wanted stand by for CW traffic clear of traffic stop weather conditions? lunch break
10-62	reply to message subject possibly wanted unable to copy, use phone check for rising water logged on/off
10-63	prepare to copy subject positive make written copy net directed to ___ need barricades
10-64	local message subject wanted message for delivery net clear, resume normal traffic field investigator
10-65	net message assignment assist officer re: 10-64 kidnapping
10-66	net message cancellation subject in observation category bathroom break
10-67	clear for next message subject is parolee prepare to copy person calling for help all units comply
10-68	dispatch message subject in charged category repeat dispatch switch channels
10-69	message received clear to copy transmission? any calls holding for me? sniper

10-70s

Code	Meaning(s)
10-70	fire alarm fire fire followup prowler net message chemical spill
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	enroute to location fresh coffee
10-77	ETA
10-78	need assistance major accident with injury request wrecker
10-79	notify coroner bomb threat hit & run

10-80s

Code	Meaning(s)
10-80	pursuit in progress bomb has exploded tower lights out on assignment demonstration
10-81	breathalyzer request Burgalar Alarm stop for interrogation reserve hotel room officer ___ will be at your station at vehicle maintenance civil disturbance/riot
10-82	reserve lodging stop for interrogation/arrest traffic signal out cover assistance
10-83	work/school crossing detail call station units stop transmitting at radio shop officer in trouble
10-84	advise ETA checking officer status my telephone number is ___ follow-up broken utility main
10-85	arrival delay due to ___ prepare to copy info my address is ___ loose livestock
10-86	officer on-duty utility line down
10-87	pickup or prisoner transfer pickup payroll check dead body
10-88	advise telephone station call special assignment true alarm
10-89	bomb threat send radio repair officer at academy

10-90s

Code	Meaning(s)
10-90	Alarm Going Off Bank Alarm radio repair to be at station officer at headquarters false alarm officer in chief's office missing person
10-91	pick up prisoner/suspect talk closer to the mike prepare your inspection vehicle fuel bank holdup alarm
10-92	parking violation your signal is weak officer at court
10-93	blockage please check my frequency
10-94	street racing give me a long count
10-95	prisoner/suspect in custody transmit dead carrier for 5 seconds
10-96	mental patient detain prisoner/suspect
10-97	arrived at scene test signal possible wanted person in vehicle known offender officer at court
10-98	assignment complete prison/jail break criminal history indicated officer at juvenile court
10-99	warrants/stolen indicated officer needs assistance/held hostage mission complete unable to receive your signal bathroom break Traffic stop / violator

10-100s and up

Code	Meaning(s)
10-100	bathroom break Misdemeanor Warrant dead body hot pursuit
10-109	suicide
10-200	police needed narcotics, drugs involved
10-600	livestock down
10-1000	Felony Warrant

Parodies

During the 1970s, some truck drivers and CB radio hobbyists responded to the increased use of ten-codes by the general public by inventing parodies of the ten-code with strictly humorous meanings. The best known were the 13-code [1] and the 18-code [2].

See also

• Eleven-code
• Q code
• Voice procedure
• Z code

External links

• The End of the Ten-Code? – By Tim Dees, Officer.com, 9 November 2005

• 10-4 no more? — By Megan Scott, asap (AP), 25 November 2005
• [3] — The APCO Bulletin, January 1940. The first official publication showing the 10-codes (on page 8).