CB radios are Citizen’s band radios, employing a specific range set aside for unlicensed use by the general population. They were first developed in the United States, but are also used in Australia, Canada, the United Kingdom, and Indonesia. Codes are collections or systems of words, phrases, letters, or symbols used for by those in the know about their meaning for communication that is not universally understood. CB radio codes are any codes used on CB radios, whether designed for that use or used universally or not.
CB radio codes include some systems that are more or less standard, some that are local variants of a standard, and some that are idiosyncratic, shared by a particular group or used in a particular country or region. The 10 codes — which have been used by emergency personnel, including police forces in the United States and Canada and the Royal Canadian Mounted Police (RCMP) — have been suggested for deprecation by the Department of Homeland Security (DHS) in favor of plain English, but are still used by CB radio operators. Originally called the “Ten Signals,” the 10 Codes were used in public safety for many years. The most famous 10 Codes are probably 10-4 for “OK,” 10-9 for “Repeat,” and 10-20 for “location.”
Other CB radio codes include the NATO (North Atlantic Treaty Organization) phonetic alphabet, also called the International Radiotelephony Spelling Alphabet. Letters are replaced by words with distinctive phonetics in an aim to ensure understanding, so the alphabet is rendered as Alpha, Bravo, Charlie, Delta, Echo, Foxtrot, Golf, Hotel, India, Juliet, Kilo, Lima, Mike, November, Oscar, Papa, Quebec, Romeo, Sierra, Tango, Uniform, Victor, Whiskey, X-ray, Yankee, Zulu — with slight variations of spelling and pronunciation in various international organizations. Specific Citizen’s Band radio alterations include Italy for India, Kilowatt for Kilo, Radio for Romeo, Yokohama for Yankee, and Zanzibar for Zulu.
Locally idiomatic slang forms another part of the CB radio codes. For example, in Australia, QTH means “location,” EYEBALL refers to a gathering in which CB operators meet face-to-face, and SANDBAGGINGmeans “listening to a conversation without participating.” In Australia, KOJACK refers to the police, whereas in the US, there are several different terms for police, including Kojack, LEO for “Law Enforcement Officer,” Bear, and Smokey. US CB radio codes include terms for various larger cities, including Armadillo for Amarillo, Texas; CB Town for Council Bluffs, Iowa; and Sack of Tomatoes for Sacramento, California.