Ten-code
Encyclopedia
Ten-codes, also known as ten signals, are code word
s used to represent common phrases in voice communication, particularly by law enforcement and in Citizens' Band
(CB) radio transmissions.
The codes, developed in 1937 and expanded in 1974 by the Association of Public-Safety Communications Officials-International
(APCO), allow for 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.
, District 10, located in Pesotum, Illinois
. Hopper was involved in radio for many years and saw a need to abbreviate radio transmissions on State Police
bands. Experienced radio operators know that the first syllable
of a transmission is frequently not going to be understood, but is a necessary part of "tuning in"; hence preceding every code with "ten" allows a better chance of understanding the critical portion. Also, the radios of the day were based on vacuum tube
s, with a small motor-generator, called a dynamotor, used to generate the high voltage (300–600 volts, depending on the type of radio) needed to operate the transmitter, and the dynamotor took 1/10 to 1/4 of a second to "spin up". The officers were trained to push the microphone button, then wait a moment before talking, but sometimes they would forget; preceding every code with "ten-" gave the radio transmitter time to come up to full power.
Ten-codes, especially "ten-four", first reached public recognition in the mid- to late-1950s through the popularity of TV's Highway Patrol
with Broderick Crawford
as the patrolman reaching into his cruiser to grab the mike
to answer a call, always preceding his response with "10-4!" Ten-codes were later adapted for use by CB radio
enthusiasts before its pop culture explosion in the late 1970s. The tremendous popularity of the 1975 "Convoy
" song by C. W. McCall
depicting droll conversation among CB-communicating truckers put several phrases, such as 10-4 for "understood" and what's your twenty? (10-20) for "where are you?" into common and enduring use in American English
. The song was followed by a 1978 movie Convoy, which further entrenched the use of ten-codes in casual conversation.
Codes are often used inefficiently. For instance, an exchange that could be "1 Mike 1, 10-20?" "First and Main" might be more like "1 Mike 1, what's your 10-20?" "My 20 is First and Main"—it would be more efficient to simply ask, "1 Mike 1, where are you?" "I'm at First and Main." On the other hand, there are times when the use of codes is appropriate, even if less efficient than speaking "in the clear." For instance, using discreet codes for sexual assault, homicide, suicide and other such situations can prevent the victim and family from having to hear the description being broadcast to all within earshot. Even when the meaning is known, it is less of an emotional jolt to hear a set of numbers being rattled off than to hear the word for the crime.
While ten-codes were intended to be a terse, concise, and standardized system, the proliferation of different meanings may render them useless in situations where people from different agencies and jurisdictions need to communicate. For that reason their use is expressly forbidden in the nationally-standardized Incident Command System
as is the use of other codes.
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. The New Orleans Police Department continued using 10-codes as of 2010. One solution to the inter-jurisdictional problem would be to establish a universal standard for the most common 10-codes, and disallow in ICS situations any other codes.
A basic list (10-1 through 10-39) remains available on APCO's site. Many additional codes have been added by individual local or regional first-response agencies; these are not standard across jurisdictions and may be problematic if multiple organizations must respond to the same incident. Only a handful of codes are standardized.
sections were in use by the Los Angeles Police Department
as early as the 1940s, and these code numbers are still used today instead of the corresponding ten-code. The best-known include:
Generally these are given as two sets of numbers—"One Eighty-Seven" or "Fifty-One Fifty"—with a few exceptions such as "459"—Burglary, which is given as "Four-Five-Nine".
The New York Fire Department uses its own ten-code system
New Zealand's Fire Service uses a similar "K-code" system.
The California Highway Patrol
uses eleven-codes.
Q code
and prosigns for Morse code
are used in amateur radio
, aviation and marine radio. They provide specific abbreviations for concepts related to aviation, shipping, RTTY, radiotelegraph and amateur radio. In radiotelegraph operation, a Q code is often shorter (as ten-codes require transmission of three prefix characters: 1, 0, hyphen) and provides standardization of codes, essential in international and shortwave
communication.
Z code
s are used by NATO countries in military radio communications.
Code word
In communication, a code word is an element of a standardized code or protocol. Each code word is assembled in accordance with the specific rules of the code and assigned a unique meaning...
s used to represent common phrases in voice communication, particularly by law enforcement and in Citizens' Band
Citizens' band radio
Citizens' Band radio is, in many countries, a system of short-distance radio communications between individuals on a selection of 40 channels within the 27-MHz band. Citizens' Band is distinct from the FRS, GMRS, MURS and amateur radio...
(CB) radio transmissions.
The codes, developed in 1937 and expanded in 1974 by the Association of Public-Safety Communications Officials-International
Association of Public-Safety Communications Officials-International
The Association of Public-Safety Communications Officials-International was founded in 1935 and is the world's largest organization dedicated to public safety telecommunications.APCO has developed several standards that bear its name...
(APCO), allow for brevity and standardization of message traffic. They have historically been widely used by law enforcement officers in North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
but due to the lack of standardization, in 2006 the U.S. federal government recommended they be discontinued in favor of everyday language.
History
The development of the 10-codes began in 1937, at a time when police radio channels were limited, to reduce use of speech on the radio. Credit for inventing the codes goes to Charles "Charlie" Hopper. He was the Communications Director at the Illinois State PoliceIllinois State Police
The Illinois State Police is the state police force of Illinois. Officially established in 1922, the Illinois State Police have over 3,000 personnel and 21 districts. The main facilities of the Illinois State Police Academy, which were constructed in 1968, are located in Springfield. Prior to...
, District 10, located in Pesotum, Illinois
Pesotum, Illinois
Pesotum is a village in Champaign County, Illinois, United States. The population was 551 at the 2010 census.-Geography:Pesotum is located at .According to the United States Census Bureau, the village has a total area of , all of it land.-Demographics:...
. Hopper was involved in radio for many years and saw a need to abbreviate radio transmissions on State Police
State police
State police are a type of sub-national territorial police force, particularly in Australia and the United States. Some other countries have analogous police forces, such as the provincial police in some Canadian provinces, while in other places, the same responsibilities are held by national...
bands. Experienced radio operators know that the first syllable
Syllable
A syllable is a unit of organization for a sequence of speech sounds. For example, the word water is composed of two syllables: wa and ter. A syllable is typically made up of a syllable nucleus with optional initial and final margins .Syllables are often considered the phonological "building...
of a transmission is frequently not going to be understood, but is a necessary part of "tuning in"; hence preceding every code with "ten" allows a better chance of understanding the critical portion. Also, the radios of the day were based on vacuum tube
Vacuum tube
In electronics, a vacuum tube, electron tube , or thermionic valve , reduced to simply "tube" or "valve" in everyday parlance, is a device that relies on the flow of electric current through a vacuum...
s, with a small motor-generator, called a dynamotor, used to generate the high voltage (300–600 volts, depending on the type of radio) needed to operate the transmitter, and the dynamotor took 1/10 to 1/4 of a second to "spin up". The officers were trained to push the microphone button, then wait a moment before talking, but sometimes they would forget; preceding every code with "ten-" gave the radio transmitter time to come up to full power.
Ten-codes, especially "ten-four", first reached public recognition in the mid- to late-1950s through the popularity of TV's Highway Patrol
Highway Patrol (TV series)
Highway Patrol is a syndicated action crime drama series produced 1955-1959.-Overview:Highway Patrol stars Broderick Crawford as Dan Mathews, the gruff and dedicated head of a police force in an unidentified Western state...
with Broderick Crawford
Broderick Crawford
Broderick Crawford was an Academy Award-winning American stage, film, radio and TV actor, often cast in tough-guy roles and best known for his starring role in the television series "Highway Patrol."-Early life:...
as the patrolman reaching into his cruiser to grab the mike
Microphone
A microphone is an acoustic-to-electric transducer or sensor that converts sound into an electrical signal. In 1877, Emile Berliner invented the first microphone used as a telephone voice transmitter...
to answer a call, always preceding his response with "10-4!" Ten-codes were later adapted for use by CB radio
Citizens' band radio
Citizens' Band radio is, in many countries, a system of short-distance radio communications between individuals on a selection of 40 channels within the 27-MHz band. Citizens' Band is distinct from the FRS, GMRS, MURS and amateur radio...
enthusiasts before its pop culture explosion in the late 1970s. The tremendous popularity of the 1975 "Convoy
Convoy (song)
"Convoy" is a 1975 novelty song performed by C. W. McCall that became a number-one song on both the country and pop charts in the US. Written by McCall and Chip Davis, the song spent six weeks at number one on the country charts and one week at number one on the pop charts...
" song by C. W. McCall
C. W. McCall
C. W. McCall is the pseudonym of William Dale Fries, Jr. , an American singer, activist and politician known for his truck-themed outlaw country songs.-Biography:...
depicting droll conversation among CB-communicating truckers put several phrases, such as 10-4 for "understood" and what's your twenty? (10-20) for "where are you?" into common and enduring use in American English
American English
American English is a set of dialects of the English language used mostly in the United States. Approximately two-thirds of the world's native speakers of English live in the United States....
. The song was followed by a 1978 movie Convoy, which further entrenched the use of ten-codes in casual conversation.
Replacement with plain language
As of 2011, ten-codes remain in common use, but have been phased out in some areas in favor of plain language. Nineteen states were planning to change to plain English as of the end of 2009.Codes are often used inefficiently. For instance, an exchange that could be "1 Mike 1, 10-20?" "First and Main" might be more like "1 Mike 1, what's your 10-20?" "My 20 is First and Main"—it would be more efficient to simply ask, "1 Mike 1, where are you?" "I'm at First and Main." On the other hand, there are times when the use of codes is appropriate, even if less efficient than speaking "in the clear." For instance, using discreet codes for sexual assault, homicide, suicide and other such situations can prevent the victim and family from having to hear the description being broadcast to all within earshot. Even when the meaning is known, it is less of an emotional jolt to hear a set of numbers being rattled off than to hear the word for the crime.
While ten-codes were intended to be a terse, concise, and standardized system, the proliferation of different meanings may render them useless in situations where people from different agencies and jurisdictions need to communicate. For that reason their use is expressly forbidden in the nationally-standardized Incident Command System
Incident Command System
The Incident Command System is "a systematic tool used for the command, control, and coordination of emergency response" according to the United States Federal Highway Administration...
as is the use of other codes.
In the fall of 2005, responding to inter-organizational communication problems during the rescue operations after Hurricane Katrina
Hurricane Katrina
Hurricane Katrina of the 2005 Atlantic hurricane season was a powerful Atlantic hurricane. It is the costliest natural disaster, as well as one of the five deadliest hurricanes, in the history of the United States. Among recorded Atlantic hurricanes, it was the sixth strongest overall...
, the United States Federal Emergency Management Agency
Federal Emergency Management Agency
The Federal Emergency Management Agency is an agency of the United States Department of Homeland Security, initially created by Presidential Reorganization Plan No. 1 of 1978 and implemented by two Executive Orders...
(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. The New Orleans Police Department continued using 10-codes as of 2010. One solution to the inter-jurisdictional problem would be to establish a universal standard for the most common 10-codes, and disallow in ICS situations any other codes.
List of ten-codes
While 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, an APCO Bulletin of January, 1940 lists 17 codes assigned as part of APCO Project 4; in 1973, APCO Project 14 provided a core list of codes from 10-1 to 10-39, with "optional" codes above 10-39.A basic list (10-1 through 10-39) remains available on APCO's site. Many additional codes have been added by individual local or regional first-response agencies; these are not standard across jurisdictions and may be problematic if multiple organizations must respond to the same incident. Only a handful of codes are standardized.
Related codes
California Penal CodeCalifornia Penal Code
The Penal Code of California forms the basis for the application of criminal law in the American state of California. It was originally enacted in 1872 as one of the original four California Codes, and has been substantially amended and revised since then....
sections were in use by the Los Angeles Police Department
Los Angeles Police Department
The Los Angeles Police Department is the police department of the city of Los Angeles, California. With just under 10,000 officers and more than 3,000 civilian staff, covering an area of with a population of more than 4.1 million people, it is the third largest local law enforcement agency in...
as early as the 1940s, and these code numbers are still used today instead of the corresponding ten-code. The best-known include:
- "187": Homicide
- "211": Armed Robbery
- "415": Disturbance
- "417": Man or woman with a gun
- "502": Intoxicated Driver
- "51505150 (Involuntary psychiatric hold)Section 5150 is a section of the California Welfare and Institutions Code which allows a qualified officer or clinician to involuntarily confine a person deemed to have a mental disorder that makes them a danger to him or her self, and/or others and/or gravely disabled...
": mentally disturbed person (actually a reference to the California Welfare and Institutions Code)
Generally these are given as two sets of numbers—"One Eighty-Seven" or "Fifty-One Fifty"—with a few exceptions such as "459"—Burglary, which is given as "Four-Five-Nine".
The New York Fire Department uses its own ten-code system
New Zealand's Fire Service uses a similar "K-code" system.
The California Highway Patrol
California Highway Patrol
The California Highway Patrol is a law enforcement agency of the U.S. state of California. The CHP has patrol jurisdiction over all California highways and also acts as the state police....
uses eleven-codes.
Q code
Q code
The Q code is a standardized collection of three-letter message encodings, also known as a brevity code, all of which start with the letter "Q", initially developed for commercial radiotelegraph communication, and later adopted by other radio services, especially amateur radio...
and prosigns for Morse code
Prosigns for Morse Code
In Morse code, prosigns or procedural signals are dot/dash sequences that have a special meaning in a transmission: they are a form of control character...
are used in amateur radio
Amateur radio
Amateur radio is the use of designated radio frequency spectrum for purposes of private recreation, non-commercial exchange of messages, wireless experimentation, self-training, and emergency communication...
, aviation and marine radio. They provide specific abbreviations for concepts related to aviation, shipping, RTTY, radiotelegraph and amateur radio. In radiotelegraph operation, a Q code is often shorter (as ten-codes require transmission of three prefix characters: 1, 0, hyphen) and provides standardization of codes, essential in international and shortwave
Shortwave
Shortwave radio refers to the upper MF and all of the HF portion of the radio spectrum, between 1,800–30,000 kHz. Shortwave radio received its name because the wavelengths in this band are shorter than 200 m which marked the original upper limit of the medium frequency band first used...
communication.
Z code
Z code
Z Code is a set of codes used in CW, TTY and RTTY radio communication. Actually, there are different sets of Z-codes: one originally developed by Cable & Wireless Ltd., for commercial communications in the early days of wire and radio communications, another one independently developed by NATO...
s are used by NATO countries in military radio communications.
See also
- 10-8: Officers on Duty, a short-lived ABC police drama
- CB slangCB slangCB slang is the distinctive anti-language, argot or cant which developed amongst users of citizens' band radio , especially truck drivers in the USA during the 1970s and early-1980s....
- List of international common standards
- Q codeQ codeThe Q code is a standardized collection of three-letter message encodings, also known as a brevity code, all of which start with the letter "Q", initially developed for commercial radiotelegraph communication, and later adopted by other radio services, especially amateur radio...
- Voice procedureVoice procedureVoice procedure includes various techniques used to clarify, simplify and standardize spoken communications over two-way radios, in use by the military, in civil aviation, police and fire dispatching systems, citizens' band radio , etc....
- Procedure wordProcedure wordProcedure words or prowords are words or phrases limited to radio telephone procedure used to facilitate communication by conveying information in a condensed standard form. - OUT :...
- Procedure word
- Z codeZ codeZ Code is a set of codes used in CW, TTY and RTTY radio communication. Actually, there are different sets of Z-codes: one originally developed by Cable & Wireless Ltd., for commercial communications in the early days of wire and radio communications, another one independently developed by NATO...
External links
- Los Angeles Sheriff's Department ten code list
- New York City Police Department radio signal codes
- APCO Bulletin—The APCO Bulletin, January 1940. The first official publication showing the 10-codes (see page 8).
- Association of Public Communications Officers ten code list
- Popular and substandard ten codes