Police and emergency 10 codes

Ten-codes, officially known as ten signals, are brevity codes used to represent common phrases in voice communication, particularly by law enforcement and in Citizens Band (CB) radio transmissions. The police version of ten-codes is officially known as the APCO Project 14 Aural Brevity Code.

The codes, developed during 1937–1940 and expanded in 1974 by the Association of Public-Safety Communications Officials-International (APCO), allow brevity and standardization of message traffic. They have historically been widely used by law enforcement officers in North America, but, due to the lack of standardization, in 2006 the U.S. federal government recommended they be discontinued in favor of everyday language.

History: APCO first proposed Morse code brevity codes in the June 1935 issue of The APCO Bulletin, which were adapted from the procedure symbols of the U.S. Navy, though these procedures were for communications in Morse code, not voice. In August 1935, the APCO Bulletin published a recommendation that the organization issue a handbook that described standard operating procedures, including:

A standard message form for use by all police departments.

A simple code for service dispatches relating to corrections, repetitions, etc.

A standard arrangement of the context of messages, (for example, name and description of missing person might be transmitted as follows: Name, age, height, weight, physical characteristics, clothing; if car used, the license, make, description and motor number. This information would actually be transmitted in the text of the message as follows: John Brown 28-5-9-165 medium build brown eyes dark hair dark suit light hat Mich.35 lic.W 2605 Ford S 35 blue red wheels 2345678 may go to Indiana).

A standard record system for logging the operation of the station.

Other important records in accordance with the uniform crime reporting system sponsored by the International Association of Chiefs of Police.

The development of the APCO Ten Signals began in 1937 to reduce use of speech on the radio at a time when police radio channels were limited. Credit for inventing the codes goes to Charles "Charlie" Hopper, communications director for the Illinois State Police, District 10 in Pesotum, Illinois. Hopper had been involved in radio for years and realized there was a need to abbreviate transmissions on State Police bands. Experienced radio operators knew the first syllable of a transmission was frequently not understood because of quirks in early electronics technology. Radios in the 1930s were based on vacuum tubes powered by a small motor-generator called a dynamotor. The dynamotor took from 1/10 to 1/4 of a second to "spin up" to full power. Police officers were trained to push the microphone button, then pause briefly before speaking; however, sometimes they would forget to wait. Preceding each code with "ten-" gave the radio transmitter time to reach full power. An APCO Bulletin of January 1940 lists codes assigned as part of standardization;

In 1954, APCO published an article describing a proposed simplification of the code, based on an analysis conducted by the San Diego Police Department. In the September 1955 issue of the APCO Bulletin, a revision of the Ten-Signals was proposed, and it was later adopted.

The Ten Signals were included in APCO Project Two (1967), "Public Safety Standard Operating Procedures Manual", published as study cards in APCO Project 4 (1973), "Ten Signal Cards", and then revised in APCO Project 14 (1974).

In popular culture

Ten-codes, especially "10-4" (meaning "understood") first reached public recognition in the mid- to late-1950s through the popular television series Highway Patrol, with Broderick Crawford. Crawford would reach into his patrol car to use the microphone to answer a call and precede his response with "10-4".

Ten-codes were adapted for use by CB radio enthusiasts. C. W. McCall's hit song "Convoy" (1975), depicting conversation among CB-communicating truckers, put phrases like 10-4 and what's your twenty? (10-20 for "where are you?") into common use in American English.

The movie Convoy (1978), loosely based on McCall's song, further entrenched ten-codes in casual conversation.

The ten-codes used by the New York Police Department[14] have returned to public attention thanks to the popularity of the television series Blue Bloods. However, it must be noted that the ten-codes used by the NYPD are not the same as those used in the APCO system (see below). For example, in the NYPD system, Code 10-13 means "Officer needs help," whereas in the APCO system "Officer needs help" is Code 10-33.

The New Zealand reality television show Police Ten 7 takes its name from the New Zealand Police ten-code 10-7, which means "Unit has arrived at job".

In the last episode of the anime Kekkai Sensen & Beyond, Leonardo uses the code 10-33 in a message to signal that he is in a situation beyond his control.

The syndicated internet radio countdown program "What's your Twenty"[15] is named after the code for location.

Replacement with plain language

While ten-codes were intended to be a terse, concise, and standardized system, the proliferation of different meanings can render them useless in situations when officers from different agencies and jurisdictions need to communicate.

In the fall of 2005, responding to inter-organizational 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 wide variation in meaning. The Department of Homeland Security's SAFECOM program, established in response to communication problems experienced during the September 11 attacks also advises local agencies on how and why to transition to plain language, and their use is expressly forbidden in the nationally standardized Incident Command System, as is the use of other codes.

APCO International's current position states that plain speech communications over public safety radio systems is preferred over the traditional 10-Codes and dispatch signals. As of 2011, ten-codes remain in common use in many areas, but are increasingly being phased out in favor of plain language, with nineteen states changing to plain English as of the end of 2009.

lain language

Clear Speech Procedure

In 1971, the Public Safety Department of Lakewood, Colorado published a study comparing the APCO Ten-code with the proposed Clear Speech procedure. The study used standards for judgment of both communications procedures based on The Public Safety Communications Standard Operating Procedure Manual, 1970 edition, published by APCO.

Clear Speech Procedure

Was - (Ten-Code)

Now - (Procedure Word)

10-0	Use Caution
10-1	Unable to copy - change location
10-3	Stop transmitting
10-4	Roger
10-5	Relay
10-6	Busy
10-7	Out at...
10-8	Clear
10-9	Say again

10-12	Stand by
10-13	Weather report/road report
10-15	Disturbance
10-17A	Theft
10-17B	Vandalism
10-17C	Shoplifting
10-18	Urgent
10-19	Return to...
10-20	Location

10-21	Call...
10-22	Disregard
10-23	On scene
10-25	Meet...or contact...
10-26	Detaining subject, expedite
10-27	Drivers License information on...
10-28	Registration information on...
10-29	Check for wanted on...

10-31A	Burglary
10-31B	Robbery
10-31C	Homicide
10-31D	Kidnapping
10-31E	Shooting
10-38	Traffic stop on...
10-42	Off duty
10-44	Request for...
10-46	Assist motorist
10-49	East bound green light out (etc.)
10-50	Traffic F=Fatal PD=Property Damage Hit and run Injury No injury reported Unknown Private property, location
10-56	Drunk pedestrian
10-63	Prepare to copy
10-70	Fire
10-74	Negative
10-76	En route...
10-77	ETA (Estimated time of arrival)
10-78	Request assistance
10-79	Notify coroner (to be done by phone whenever possible)
10-80	Chase
10-89	Bomb threat
10-90	Alarm (type of alarm)
10-91	Pick up prisoner
10-92	Parking complaint
10-95	Prisoner in custody
10-97	Check traffic signal
10-98	Prison/jail break
10-99	Wanted/stolen

Roger—To be used as acknowledgement.

AFFIRMATIVE—To be used when "yes" is needed

HELP—To be used when in danger and urgent assistance is needed.