Ten-codes, properly known as ten signals, are
code words used to represent common phrases in voice communication, particularly by law enforcement and in Citizen's Band (CB) 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 some departments have controversially attempted to prohibit their use. [ [http://www.washingtonpost.com/wp-dyn/content/article/2006/11/12/AR2006111201098.html Va. State Police Swap '10-4' For 'Message Understood'] ]
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. [Federal Emergency Management Agency. [http://www.fema.gov/emergency/nims/faq/compliance.shtm#9| "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."] 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 Policeof eight codes as part of their communication.
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 "Charlie" Hopper. He was the Communications Director at the Illinois State Police, District 10, located in Urbana, Illinois. Hopper was involved in radio for many years and saw a need to abbreviate radio transmissions on State Police bands.cite web
title=The End of 10-Codes?
month=August | year=2006|accessdate=2006-10-11] 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. Ten-codes were later adapted for use by
CB radioenthusiasts before its pop culture explosion in the late 1970s. The tremendous popularity of the 1975 "Convoy" song by C.W. McCalldepicting 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.
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 Securityreportedly has plans to do away with 10-codes as well, in favor of "Plain English" while the nationally-standardized Incident Command Systemspecifically prohibits ten-codes. As of CURRENTYEAR, ten-codes remain in common use.
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.
* 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".
10-100s and up
-! Code !! Meaning(s)
* Dead body
* Hot pursuit
* Riot Conditions Exist
* Controlled substance
* Starting Security Check
* (polite)"Restroom break".
*Ending Security Check
*Dead on Arrival (DOA)
*Officer in danger
*"Narcotics, drugs involved"
*Police required immediately
Other Police Codes
Some other police codes are as follows:
*Involuntary Psychiatric Hold
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 [http://homepage.ntlworld.com/ianjpage/cb/13Code.htm 13-Code] ] and the 18-code. [http://homepage.ntlworld.com/ianjpage/cb/18Code.htm 18-Code] ] .
* "", a short-lived ABC
* [http://www.lacdcs.com/training-tencodes-endpage.html Los Angeles Sheriff's Department DCS Ten Codes List]
* [http://www.officer.com/article/article.jsp?siteSection=19&id=26605 The End of the Ten-Code?] – By Tim Dees, Officer.com,
9 November 2005
* [http://asap.ap.org/stories/185732.s 10-4 no more?] — By Megan Scott, asap (AP),
25 November 2005
* [http://www.apcohistory.org/pdf/1940-01-jan_pages1-12.pdf APCO Bulletin] — The APCO Bulletin, January 1940. The first official publication showing the 10-codes (on page 8).
* [http://spiffy.ci.uiuc.edu/~kline/Stuff/ten-codes.html Official Ten-Code List]
* [http://10-4.org/ Ten-Codes in Russian]
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