Police units in the United States tend to use a tactical designator (or tactical callsign) consisting of a letter of the police radio alphabet followed by one or two numbers. For example, "Mary One" might identify the head of a city's homicide division. Police and fire department radio systems are assigned official callsigns, however. Examples are KQY672 and KYX556. The official headquarters callsigns are usually announced at least hourly, and more frequently by Morse code.
The United States Army uses tactical designators that change daily. They normally consist of letter-number-letter prefixes identifying a unit, followed by a number-number suffix identifying the role of the person using the callsign.
A country code is a short alphanumeric identification code for countries and dependent areas. Its primary use is in data processing and communications. Several identification systems have been developed.
The International Telecommunication Union (ITU) allocates call sign prefixes for radio and television stations of all types. They also form the basis for, but may not exactly match, aircraft registration identifiers. These prefixes are agreed upon internationally, and are a form of country code. A call sign can be any number of letters and numerals but each country must only use call signs that begin with the characters allocated for use in that country.
The (International) Radiotelephony Spelling Alphabet, commonly known as the NATO phonetic alphabet, is the most widely used set of clear code words for communicating the letters of the Roman alphabet. Technically a radiotelephonic spelling alphabet, it goes by various names, including NATO spelling alphabet, ICAO phonetic alphabet and ICAO spelling alphabet. The ITU phonetic alphabet and figure code is a rarely used variant that differs in the code words for digits.
The Q-code is a standardised collection of three-letter codes that each start with the letter "Q". It is an operating signal initially developed for commercial radiotelegraph communication and later adopted by other radio services, especially amateur radio. To distinguish the use of a Q-code transmitted as a question from the same Q-code transmitted as a statement, operators either prefixed it with the military network question marker "INT" or suffixed it with the standard Morse question mark UD.
The APCO phonetic alphabet, a.k.a. LAPD radio alphabet, is the term for an old competing spelling alphabet to the ICAO radiotelephony alphabet, defined by the Association of Public-Safety Communications Officials-International from 1941 to 1974, that is used by the Los Angeles Police Department (LAPD) and other local and state law enforcement agencies across the state of California and elsewhere in the United States. It is the "over the air" communication used for properly understanding a broadcast of letters in the form of easily understood words. Despite often being called a "phonetic alphabet", it is not a phonetic alphabet for transcribing phonetics.
Radiotelephony procedure includes various techniques used to clarify, simplify and standardize spoken communications over two-way radios, in use by the armed forces, in civil aviation, police and fire dispatching systems, citizens' band radio (CB), and amateur radio.
A United States military occupation code, or a military occupational specialty code, is a nine-character code used in the United States Army and United States Marine Corps to identify a specific job. In the United States Air Force, a system of Air Force Specialty Codes (AFSC) is used. In the United States Navy, a system of naval ratings and designators are used along with the Navy Enlisted Classification (NEC) system. A system of ratings is also used in the United States Coast Guard.
An aircraft registration is a code unique to a single aircraft, required by international convention to be marked on the exterior of every civil aircraft. The registration indicates the aircraft's country of registration, and functions much like an automobile license plate or a ship registration. This code must also appear in its Certificate of Registration, issued by the relevant civil aviation authority (CAA). An aircraft can only have one registration, in one jurisdiction, though it is changeable over the life of the aircraft.
In broadcasting and radio communications, a call sign is a unique identifier for a transmitter station. A call sign can be formally assigned by a government agency, informally adopted by individuals or organizations, or even cryptographically encoded to disguise a station's identity.
A location identifier is a symbolic representation for the name and the location of an airport, navigation aid, or weather station, and is used for staffed air traffic control facilities in air traffic control, telecommunications, computer programming, weather reports, and related services.
This is a list of airline codes. The table lists IATA's two-character airline designators, ICAO's three-character airline designators and the airline call signs. Historical assignments are also included.
Tail codes are markings usually on the vertical stabilizer of U.S. military aircraft that help identify the aircraft's unit and/or base assignment. This is not the same as the serial number, bureau number, or aircraft registration which provide unique aircraft identification.
A spelling alphabet is a set of words used to represent the letters of an alphabet in oral communication, especially over a two-way radio or telephone. The words chosen to represent the letters sound sufficiently different from each other to clearly differentiate them. This avoids any confusion that could easily otherwise result from the names of letters that sound similar, except for some small difference easily missed or easily degraded by the imperfect sound quality of the apparatus. For example, in the Latin alphabet, the letters B, P, and D sound similar and could easily be confused, but the words "bravo", "papa" and "delta" sound completely different, making confusion unlikely.
In the United States, all military aircraft display a serial number to identify individual aircraft. These numbers are located on the aircraft tail, so they are sometimes referred to unofficially as "tail numbers". On the Northrop Grumman B-2 Spirit bomber, lacking a tail, the number appears on the nose gear door. Individual agencies have each evolved their own system of serial number identification. Aircraft serials are part of the Aircraft Visual Identification System, which also includes the aircraft's tail code and Modex.
Amateur radio call signs are allocated to amateur radio operators around the world. The call signs are used to legally identify the station or operator, with some countries requiring the station call sign to always be used and others allowing the operator call sign instead.
Belgian owned and operated aircraft are identified by either registration letters or serial numbers for military aircraft.
Maritime call signs are call signs assigned as unique identifiers to ships and boats. All radio transmissions must be individually identified by the call sign. Merchant and naval vessels are assigned call signs by their national licensing authorities.
Military call signs are call signs or specialized form of nickname assigned as unique identifiers to military communications. In wartime, monitoring an adversary's communications can be a valuable form of intelligence. Consistent call signs can aid in this monitoring, so in wartime, military units often employ tactical call signs and sometimes change them at regular intervals. In peacetime, some military stations will use fixed call signs in the international series.
Aviation call signs are communication call signs assigned as unique identifiers to aircraft.
Broadcast call signs are call signs assigned as unique identifiers to radio stations and television stations. While broadcast radio stations will often brand themselves with plain-text names, identities such as "cool FM", "rock 105" or "the ABC network" are not globally unique. Another station in another city or country may have a similar brand, and the name of a broadcast station for legal purposes is normally its internationally recognised ITU call sign. Some common conventions are followed around the world.