A three-letter acronym (TLA), or three-letter abbreviation is, as the phrase suggests, an

abbreviation An abbreviation () is a shortened form of a word or phrase, by any method including shortening (linguistics), shortening, contraction (grammar), contraction, initialism (which includes acronym), or crasis. An abbreviation may be a shortened for ...

consisting of three letters. The term has a special status among abbreviations and to some is considered humorous since the term ''TLA'' is itself a three-letter acronym; it is an autological word. Most TLAs are

initialism An acronym is a type of abbreviation consisting of a phrase whose only pronounced elements are the initial letters or initial sounds of words inside that phrase. Acronyms are often spelled with the initial letter of each word in all caps wi ...

s (the initial letter of each word of a phrase), but most are not

acronym An acronym is a type of abbreviation consisting of a phrase whose only pronounced elements are the initial letters or initial sounds of words inside that phrase. Acronyms are often spelled with the initial Letter (alphabet), letter of each wor ...

s in the strict sense since they are pronounced by saying each letter, as in '' APA'' . Some are true acronyms (pronounced as a word) such as CAT (as in CAT scan) which is pronounced as the animal.

Examples

* Academic testing: ACT,

SAT The SAT ( ) is a standardized test widely used for college admissions in the United States. Since its debut in 1926, its name and Test score, scoring have changed several times. For much of its history, it was called the Scholastic Aptitude Test ...

* Air Navigation Services ( ANS): AIS, ATC, ATM, ATS, CNS, FIS, MET, and SAR * IATA airport codes: LAX and LHR * Business: CEO, CFO, and other C-level officers * Canine registries: AKC and CKC * Chemistry, biology, and pharmaceuticals: GMO, LSD, and MSG * Clinical medicine: CAD, CHF, PSA, and SOB * Communications shorthand: LOL and OMG * Computer phrases: CPU, DOS, RAM,

ROM Rom, or ROM may refer to: Biomechanics and medicine * Risk of mortality, a medical classification to estimate the likelihood of death for a patient * Rupture of membranes, a term used during pregnancy to describe a rupture of the amniotic sac * ...

, and GNU * Corporations:

BMW Bayerische Motoren Werke AG, trading as BMW Group (commonly abbreviated to BMW (), sometimes anglicised as Bavarian Motor Works), is a German multinational manufacturer of vehicles and motorcycles headquartered in Munich, Bavaria, Germany. Th ...

IBM International Business Machines Corporation (using the trademark IBM), nicknamed Big Blue, is an American Multinational corporation, multinational technology company headquartered in Armonk, New York, and present in over 175 countries. It is ...

, AMD, KFC and

NEC is a Japanese multinational information technology and electronics corporation, headquartered at the NEC Supertower in Minato, Tokyo, Japan. It provides IT and network solutions, including cloud computing, artificial intelligence (AI), Inte ...

* Countries: SRI, USA,

CAR A car, or an automobile, is a motor vehicle with wheels. Most definitions of cars state that they run primarily on roads, seat one to eight people, have four wheels, and mainly transport people rather than cargo. There are around one billio ...

UAE The United Arab Emirates (UAE), or simply the Emirates, is a country in West Asia, in the Middle East, at the eastern end of the Arabian Peninsula. It is a federal elective monarchy made up of seven emirates, with Abu Dhabi serving as i ...

DRC The Democratic Republic of the Congo (DRC), also known as the DR Congo, Congo-Kinshasa, or simply the Congo (the last ambiguously also referring to the neighbouring Republic of the Congo), is a country in Central Africa. By land area, it is t ...

, etc. * Currency:

USD The United States dollar (symbol: $; currency code: USD) is the official currency of the United States and several other countries. The Coinage Act of 1792 introduced the U.S. dollar at par with the Spanish silver dollar, divided it int ...

, GBP, RMB, and CHF * Famous people: SRK, FDR, JFK, MJK, MLK, OBL, RBG, RDJ, RFK, and RMS * File extensions: JPG,

PDF Portable document format (PDF), standardized as ISO 32000, is a file format developed by Adobe Inc., Adobe in 1992 to present documents, including text formatting and images, in a manner independent of application software, computer hardware, ...

, and XLS * Military and weaponry: BFR and RPG * Musical groups: R.E.M., XTC,

TLC TLC may refer to: Arts and entertainment Television * ''TLC'' (TV series), a 2002 British situational comedy television series that aired on BBC2 * TLC (TV network), formerly the Learning Channel, an American cable TV network ** TLC (Asia), an A ...

, E.L.O., MC5, GBH, O.A.R., MDC, D.R.I., JFA *

Personal advertisement A personal advertisement, sometimes called a contact ad, is a form of classified advertising in which a person seeks to find another person for friendship, romance, marriage, or sexual activity. In British English, it is commonly known as an adve ...

s: SBM for single black male, STR for short-term relationship * Political parties: BJP, CCP, GOP, and AAP * Religion: LDS, SBC, and SDA *

Ship prefix A ship prefix is a combination of letters, usually abbreviations, used in front of the name of a civilian or naval ship that has historically served numerous purposes, such as identifying the vessel's mode of propulsion, purpose, or ownership/na ...

es: HMS, USS, and RMS * Sports organizations: NFL, MLB, (North America); AFL, and NRL (Australia); NPB (Japan); ACB, LFP (Spain); IPL (India), EPL (England), WBO * State postal abbreviations: NSW, QLD, VIC, and TAS (Australia) *

Television network A television broadcaster or television network is a telecommunications network for the distribution of television show, television content, where a central operation provides programming to many television stations, pay television providers or ...

s: ABC (

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

, U.S.),

BBC The British Broadcasting Corporation (BBC) is a British public service broadcaster headquartered at Broadcasting House in London, England. Originally established in 1922 as the British Broadcasting Company, it evolved into its current sta ...

(UK), CBC (

Canada Canada is a country in North America. Its Provinces and territories of Canada, ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, making it the world's List of coun ...

Japan Japan is an island country in East Asia. Located in the Pacific Ocean off the northeast coast of the Asia, Asian mainland, it is bordered on the west by the Sea of Japan and extends from the Sea of Okhotsk in the north to the East China Sea ...

), and

NHK , also known by its Romanization of Japanese, romanized initialism NHK, is a Japanese public broadcasting, public broadcaster. It is a statutory corporation funded by viewers' payments of a television licence, television license fee. NHK ope ...

(Japan) * Three-letter agencies: CIA,

FBI The Federal Bureau of Investigation (FBI) is the domestic Intelligence agency, intelligence and Security agency, security service of the United States and Federal law enforcement in the United States, its principal federal law enforcement ag ...

, CBI, FSB, and NSA * Traffic offenses: DUI, DWI, GTA, OVI * Wars and political conflicts: HYW and WWI

History and origins

The exact phrase ''three-letter acronym'' appeared in the sociology literature in 1975. Three-letter acronyms were used as

mnemonic A mnemonic device ( ), memory trick or memory device is any learning technique that aids information retention or retrieval in the human memory, often by associating the information with something that is easier to remember. It makes use of e ...

s in biological sciences, from 1977 and their practical advantage was promoted by Weber in 1982. They are used in many other fields, but the term TLA is particularly associated with computing. In 1980, the manual for the Sinclair

ZX81 The ZX81 is a home computer that was produced by Sinclair Research and manufactured in Dundee, Scotland, by Timex Corporation. It was launched in the United Kingdom in March 1981 as the successor to Sinclair's ZX80 and designed to be a low-c ...

home computer used and explained TLA. Steven Vickers ''ZX81 Basic Programming'', Sinclair Research Limited, page 161 "As you can see, everything has a three letter abbreviation (TLA)." The specific generation of three-letter acronyms in computing was mentioned in a JPL report of 1982.TDA Progress Report
R. Hull (1982) An Introduction to the new Productivity Information Management System page 176 In 1988, in a paper titled "On the Cruelty of Really Teaching Computing Science", eminent computer scientist

Edsger W. Dijkstra Edsger Wybe Dijkstra ( ; ; 11 May 1930 – 6 August 2002) was a Dutch computer scientist, programmer, software engineer, mathematician, and science essayist. Born in Rotterdam in the Netherlands, Dijkstra studied mathematics and physics and the ...

wrote (disparagingly), "No endeavour is respectable these days without a TLA" By 1992 it was in a

Microsoft Microsoft Corporation is an American multinational corporation and technology company, technology conglomerate headquartered in Redmond, Washington. Founded in 1975, the company became influential in the History of personal computers#The ear ...

handbook.

Combinatorics

The number of possible three-letter abbreviations using the 26 letters of the alphabet from A to Z (AAA, AAB, ... to ZZY, ZZZ) is 26 × 26 × 26 = 17,576. Allowing a single digit 0-9 increases this by 26 × 26 × 10 = 6,760 for each position, such as 2FA, P2P, or WW2, giving a total of 37,856 such three-character strings. Out of the 17,576 possible TLAs that can be created using 3 uppercase letters, at least 94% of them had been used at least once in a dataset of 18 million scientific article abstracts. Three-letter acronyms are the most common type of acronym in scientific research papers, with acronyms of length 3 being twice as common as those of length 2 or 4. In standard English, WWW is the TLA whose pronunciation requires the most

syllable A syllable is a basic unit of organization within a sequence of speech sounds, such as within a word, typically defined by linguists as a ''nucleus'' (most often a vowel) with optional sounds before or after that nucleus (''margins'', which are ...

s—typically nine. The usefulness of a TLA typically comes from its being quicker to say than the phrase it represents; however saying 'WWW' in English requires three times as many syllables as the phrase it is meant to abbreviate (World Wide Web). "WWW" is sometimes abbreviated to "dubdubdub" in speech.

References

{{Reflist Abbreviations Acronyms

Examples

History and origins

Combinatorics

See also

References