Ten-code
Ten-codes, properly known as ten signals, are code words 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, although some departments have controversially attempted to prohibit their use.[1]
Historic overview
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 to the originator goes to Charles "Charlie" Hopper. He was the Communications Director at the Illinois State Police, 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.[2] 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 tubes, 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, and wait a moment, then talk, but sometimes they would forget and preceding every code with "ten-" gave the radio transmitter time to come up to full power.
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.
Use of ten-codes
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, and the use by the Port Authority Police of eight codes as part of their communication. However, codes are often used inappropriately. For instance, an exchange which might be "1 Mike 1, 10-20?" "First and Main" will actually 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 most 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.
When ten-codes should not be used
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 Incident Command System as is the use of other codes.[3]
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 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-codes as well, in favor of "Plain English"[2] while the nationally-standardized Incident Command System specifically prohibits ten-codes. As of 2024, ten-codes remain in common use.
Ten-codes should also be avoided in services such as amateur radio where other existing standards (Q code and prosigns for Morse code) are already long established. Aviation and marine radio is better served by Q-code, as the ten-code phrase lists were designed primarily for local police tasks while Q-code provides specific abbreviations for concepts related to aviation, shipping, RTTY, radiotelegraph and amateur radio.[4] 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.
Mingled codes
In addition, many agencies mingle various codes, especially those which were using radio dispatch before the ten-codes were developed. For instance, the Los Angeles Police Department, which pioneered law enforcement radio communications, largely set the standard for law enforcement communications in California. Dispatchers began using California Penal Code sections in their broadcasts in 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), "5150" (Mentally Ill Person). 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 well-known "420" for marijuana, however, originates from neither.[5]
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,[6] 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,[7] with "optional" codes above 10-39.[8]
A basic list (10-1 through 10-39) remains available on APCO's site as http://www.apco911.org/new/commcenter911/downloads/10codes.pdf 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 organisations must respond to the same incident. Only a handful of codes are standardized.
The following list, given in ascending order and grouped by decade, illustrates the current usage of various ten-codes[9]. 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
10-0s | 10-10s | 10-20s | 10-30s | 10-40s | 10-50s | 10-60s | 10-70s | 10-80s | 10-90s | 10-100s and up |
Code | Meaning(s) |
---|---|
10-00 |
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10-0 |
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10-1 |
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10-2 |
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10-3 |
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10-4 |
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10-5 |
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10-6 |
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10-7 |
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10-8 |
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10-9 |
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10-10s
10-0s | 10-10s | 10-20s | 10-30s | 10-40s | 10-50s | 10-60s | 10-70s | 10-80s | 10-90s | 10-100s and up |
Code | Meaning(s) |
---|---|
10-10 |
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10-11 |
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10-12 |
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10-13 |
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10-14 |
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10-15 |
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10-16 |
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10-17 |
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10-18 |
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10-19 |
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10-20s
10-0s | 10-10s | 10-20s | 10-30s | 10-40s | 10-50s | 10-60s | 10-70s | 10-80s | 10-90s | 10-100s and up |
Code | Meaning(s) |
---|---|
10-20 |
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10-21 |
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10-22 |
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10-23 |
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10-24 |
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10-25 |
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10-26 | |
10-27 |
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10-28 |
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10-29 |
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10-30s
10-0s | 10-10s | 10-20s | 10-30s | 10-40s | 10-50s | 10-60s | 10-70s | 10-80s | 10-90s | 10-100s and up |
Code | Meaning(s) |
---|---|
10-30 |
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10-31 |
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10-32 | |
10-33 |
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10-34 |
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10-35 |
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10-36 |
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10-37 |
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10-38 |
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10-39 |
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10-40s
10-0s | 10-10s | 10-20s | 10-30s | 10-40s | 10-50s | 10-60s | 10-70s | 10-80s | 10-90s | 10-100s and up |
Code | Meaning(s) |
---|---|
10-40 |
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10-41 |
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10-42 |
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10-43 |
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10-44 |
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10-45 |
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10-46 |
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10-47 |
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10-48 |
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10-49 |
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10-50s
10-0s | 10-10s | 10-20s | 10-30s | 10-40s | 10-50s | 10-60s | 10-70s | 10-80s | 10-90s | 10-100s and up |
Code | Meaning(s) |
---|---|
10-50 |
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10-51 |
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10-52 |
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10-53 |
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10-54 |
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10-55 |
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10-56 |
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10-57 |
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10-58 |
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10-59 |
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10-60s
10-0s | 10-10s | 10-20s | 10-30s | 10-40s | 10-50s | 10-60s | 10-70s | 10-80s | 10-90s | 10-100s and up |
Code | Meaning(s) |
---|---|
10-60 |
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10-61 |
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10-62 |
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10-63 |
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10-64 |
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10-65 |
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10-66 |
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10-67 |
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10-68 |
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10-69 |
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10-70s
10-0s | 10-10s | 10-20s | 10-30s | 10-40s | 10-50s | 10-60s | 10-70s | 10-80s | 10-90s | 10-100s and up |
Code | Meaning(s) |
---|---|
10-70 |
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10-71 |
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10-72 |
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10-73 |
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10-74 |
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10-75 |
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10-76 |
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10-77 |
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10-78 |
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10-79 |
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10-80s
10-0s | 10-10s | 10-20s | 10-30s | 10-40s | 10-50s | 10-60s | 10-70s | 10-80s | 10-90s | 10-100s and up |
Code | Meaning(s) |
---|---|
10-80 |
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10-81 |
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10-82 |
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10-83 |
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10-84 |
|
10-85 |
A. Fair B. Poor C. Critical D. Possible Fatality E. Obvious Fatality |
10-86 |
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10-87 |
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10-88 |
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10-89 |
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10-90s
10-0s | 10-10s | 10-20s | 10-30s | 10-40s | 10-50s | 10-60s | 10-70s | 10-80s | 10-90s | 10-100s and up |
Code | Meaning(s) |
---|---|
10-90 |
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10-91 |
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10-92 |
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10-93 |
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10-94 |
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10-95 |
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10-96 |
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10-97 |
J1 Arrest Record Verified By Fingerprints J2 Could Be Armed/Dangerous J3 Has Assaulted Officers
|
10-98 |
|
10-99 |
J2 Felony J3 May Be Armed J4 Use Extreme Caution
|
10-100s and up
10-0s | 10-10s | 10-20s | 10-30s | 10-40s | 10-50s | 10-60s | 10-70s | 10-80s | 10-90s | 10-100s and up |
Code | Meaning(s) |
---|---|
10-100 |
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10-101 |
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10-105 |
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10-108 |
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10-109 |
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10-110 |
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10-200 |
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10-1000 |
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10-2000 |
|
Other police codes
Some other police codes are as follows:
11-99
- Officer Needs Assistance (CHP)
187
- Homicide
211
- Armed robbery
253
- Canadian Criminal Code Section for impaired driver
- Omaha police code for indecent exposure [10]
415
- Fight in progress
417
- Person with a gun
459
- Burglary
502
- Intoxicated driver
999
- Urgent help needed
- Officer in immediate life-threatening danger
- Officer down
2301
- Public Intoxication
148/149
- DUI/DWI
9560
- Mentally Ill
- Mentally Ill Person
- Involuntary Psychiatric Hold
1192
- DWI
Code 1
- Non-Urgent, Do so at your convenience
Code 2
- Urgent
Code 3
- Emergency, lights and siren
Code 4
- Subject in custody, situation under control, no further assistance needed
Code 6
- Standing by at ___
Code 7
- Meal break
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[11] and the 18-code.[citation needed]
Misuse
People sometimes use the phrase "10-4-9er" when they actually mean "10-4" (affirmative) which could create confusion with the code "10-49" which means:
- Traffic light out
- EMERGENCY, clear air
- En route to assignment
- Any traffic/pending calls for this unit?
- Warrant
- Pedestrian on freeway
- Serving warrant
- Intoxicated/reckless driver
Often when this mistake is made, the offender will add the phrase "good buddy" ("10-4-9er good buddy") which only makes it worse.
References
- ^ Va. State Police Swap '10-4' For 'Message Understood'
- ^ a b James Careless (2006). "The End of 10-Codes?". Retrieved 2006-10-11.
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ignored (help) - ^ Federal Emergency Management Agency. Frequently Asked Questions - Compliance: NIMS Compliance - Overview Accessed: 05/08/2008 "Q: Our 911 center, which receives and dispatches emergency and non-emergency calls, has told us that we may not use 10-codes at all. I gather we must use plain language when using NIMS ICS. Is that correct? A: Yes, when engaged in incident response using ICS, plain language is required. The value of using 10-codes for simplicity and speed is lost when members of the response team are unaware of their meanings, as may occur in a multi-jurisdiction / multi-agency response event. As 10-codes used in one jurisdiction, or agency, are not the same as those used in another, it is important that responders and incident managers use common terminology to prevent misunderstanding in an emergency situation. While plain English is not required for internal operations, it is encouraged over 10-codes to promote familiarity within operational procedures used in emergencies."
- ^ http://www.portland-amateur-radio-club.org.uk/resources/q-codes.pdf
- ^ http://www.snopes.com/language/stories/420.asp
- ^ http://www.apcointl.org/new/government/positionstatements.php
- ^ http://www.911dispatch.com/info/tencode.html
- ^ METCAD, primary 9-1-1 operator for Champaign County, Illinois
- ^ http://spiffy.ci.uiuc.edu/~kline/Stuff/ten-codes.html
- ^ http://www.radiolabs.com/police-codes.html
- ^ http://cmccord.co.uk/Radio/13-Codes.htm
See also
- 10-8: Officers on Duty, a short-lived ABC police drama
- CB slang
- Eleven-code
- NYPD ten-codes
- Q code
- Voice procedure
- Z code
External links
- Los Angeles Sheriff's Department Ten Codes List
- 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
- APCO Bulletin — The APCO Bulletin, January 1940. The first official publication showing the 10-codes (on page 8).
- Official Ten-Code List