Editing Ten-code (section)

==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.<ref>{{cite web|title=The APCO Bulletin (June 1935)|url=http://28011b0082f55a9e1ec0-aecfa82ae628504f4b1d229bd9030ae1.r13.cf1.rackcdn.com/june-1935.pdf|access-date=15 March 2016|url-status=live|archive-url=https://web.archive.org/web/20160316141346/http://28011b0082f55a9e1ec0-aecfa82ae628504f4b1d229bd9030ae1.r13.cf1.rackcdn.com/june-1935.pdf|archive-date=16 March 2016}}</ref>

In August 1935, the APCO Bulletin published a recommendation that the organization issue a handbook that described standard operating procedures, including:<ref>{{Cite web|url=http://28011b0082f55a9e1ec0-aecfa82ae628504f4b1d229bd9030ae1.r13.cf1.rackcdn.com/august-1935.pdf|title=Special APCO Bulletin|date=August 1935}}</ref>
# 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<ref>{{Cite web|url=https://apconetforum.org/eweb/downloads/PolicyManual061509.pdf|title=APCO Project Series}}</ref> 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|State Police]] bands.<ref name="end10codes">{{cite web|url=http://www.hendonpub.com/resources/article_archive/results/details?id=3615|title=The End of 10-Codes?|date=August 2006|author=James Careless|access-date=15 March 2016|url-status=live|archive-url=https://web.archive.org/web/20160316230251/http://www.hendonpub.com/resources/article_archive/results/details?id=3615|archive-date=16 March 2016}}</ref> 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 tube]]s 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 standardisation.<ref name=Bulletin>[http://28011b0082f55a9e1ec0-aecfa82ae628504f4b1d229bd9030ae1.r13.cf1.rackcdn.com/1940-01-p008-200.pdf http://28011b0082f55a9e1ec0-aecfa82ae628504f4b1d229bd9030ae1.r13.cf1.rackcdn.com/1940-01-p008-200.pdf] {{webarchive|url=https://web.archive.org/web/20170810212357/http://28011b0082f55a9e1ec0-aecfa82ae628504f4b1d229bd9030ae1.r13.cf1.rackcdn.com/1940-01-p008-200.pdf |date=2017-08-10 }}, p.8</ref>

In 1954, APCO published an article describing a proposed simplification of the code, based on an analysis conducted by the San Diego Police Department.<ref>{{Cite web|url=http://www.apcohistory.org/apco-collection/search/profile/article/A30356|title=Codes And Signals - More Discussion On The Radio Code Problems}}</ref> In the September 1955 issue of the APCO Bulletin, a revision of the Ten-Signals was proposed,<ref>{{Cite web|url=http://28011b0082f55a9e1ec0-aecfa82ae628504f4b1d229bd9030ae1.r13.cf1.rackcdn.com/1955-09-pp008-200.pdf|title=Proposed Revision Of "10" Signals}}</ref> 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).<ref>{{cite web|title=The Origin of The Ten Code|url=http://www.freqofnature.com/index.php?m=articles&p=brevity%20codes|access-date=27 April 2015|url-status=live|archive-url=https://web.archive.org/web/20150618100816/http://www.freqofnature.com/index.php?m=articles&p=brevity%20codes|archive-date=18 June 2015}}</ref><ref>{{cite web|title=APCO Projects|url=https://www.apcointl.org/about-apco/apco-projects.html|access-date=27 April 2015|url-status=live|archive-url=https://web.archive.org/web/20150618160414/https://www.apcointl.org/about-apco/apco-projects.html|archive-date=18 June 2015}}</ref><ref>[http://www.911dispatch.com/info/tencode.html 9-Code, 10-Code.] {{webarchive|url=https://web.archive.org/web/20150320040332/http://www.911dispatch.com/info/tencode.html |date=2015-03-20 }} Dispatch Magazine online.</ref><ref name="Rafik Jabbour">{{cite web|title=Official Ten-Code List Association of Public Communications Officers (APCO)|url=http://spiffy.ci.uiuc.edu/~kline/Stuff/ten-codes.html|url-status=dead|archive-url=https://web.archive.org/web/20071013030055/http://spiffy.ci.uiuc.edu/~kline/Stuff/ten-codes.html|archive-date=2007-10-13}}</ref>

===In popular culture===
Ten-codes, especially "10-4" (meaning "understood") first reached public recognition in the mid- to late-1950s through the television series ''[[Highway Patrol (U.S. TV series)|Highway Patrol]]'', with [[Broderick Crawford]].{{citation needed|date=April 2020}}

Ten-codes were adapted for use by [[Citizens band radio|CB radio]] enthusiasts. [[C. W. McCall]]'s hit song "[[Convoy (song)|Convoy]]" (1975), depicting conversation among CB-communicating [[trucker]]s, put phrases like "10-4" and "what's your twenty?" (10-20 for "where are you?") into common use in American English.{{citation needed|date=April 2020}}

The movie ''[[Convoy (1978 film)|Convoy]]'' (1978), loosely based on McCall's song, further entrenched ten-codes in casual conversation, as did the movie ''[[Smokey and the Bandit]].

The New Zealand [[reality television]] show ''[[Ten 7 Aotearoa]]'' (formerly ''Police Ten 7'') takes its name from the New Zealand Police ten-code 10-7, which means "Unit has arrived at job".<ref>{{Cite web |last=Admin |first=Blow on the Pie |title=NATIONAL RADIO CODES / POLICE {{!}} BlowonthePie - For New Zealand Scanner Codes and more |url=https://blowonthepie.co.nz/emergency-codes/national-radio-codes-police/ |access-date=2025-03-02 |language=en-US}}</ref><ref>{{Cite web |last=Screen |first=NZ On |title=Police Ten 7 {{!}} Series {{!}} Television {{!}} NZ On Screen |url=https://www.nzonscreen.com/title/police-ten-7-2002/series#:~:text=Taking%20its%20name%20from%20police,began%20presenting%20in%20September%202015. |access-date=2025-03-02 |website=www.nzonscreen.com |language=en}}</ref>