Three-letter acronym

A three-letter acronym, three-letter abbreviation, or TLA is an abbreviation, specifically an acronym, alphabetism, or initialism, consisting of three letters. These are usually the initial letters of the words of the phrase abbreviated, and are written in capital letters (upper case); three-letter abbreviations such as etc. and Mrs. are not three-letter acronyms, but "TLA" itself is a TLA (an example of a self-referencing definition).

Most three-letter abbreviations are initialisms: all the letters are pronounced as the names of letters, as in APA /ˌeɪpiːˈeɪ/ AY-pee-AY. Some are acronyms pronounced as a word; computed axial tomography, CAT, is almost always pronounced as the animal's name in "CAT scan".

Examples

• Countries: UAE and USA
• American Presidents: FDR, JFK, and LBJ
• Computer phrases: CPU, DOS, RAM, ROM, and GNU, a recursive TLA that stands for "GNU's not Unix"
• File extensions: JPG, and MP3
• Corporations: IBM, AMD and NEC
• Business: CEO, CFO and other C-level officers
• Three Letter Agencies: CIA, FBI, FSB, and NSA
• Television networks: ABC (Aus., U.S.), BBC (UK), CBC (Canada, Japan), and NHK (Japan)
• Personal advertisements: SBM for Single Black Male, STR for Short Term Relationship
• Chemistry, biology, pharmaceuticals: GMO, LSD and MSG
• Religion: LDS
• Clinical medicine: CAD and CHF
• Communications shorthand: LOL and OMG
• Military and weaponry: BFR and RPG
• Wars and political conflicts: HYW and WWI
• ISO currency codes: EUR, GBP, JPY and USD
• IATA airport codes: LAX and LHR
• Academic testing: ACT, HSC (Bangladesh, India and Pakistan, NSW, Vic, UK) and SAT
• Canine registries: AKC and CKC
• Sports leagues: NFL, MLB, (North America); AFL and NRL (Australia); NPB (Japan); ACB, LFP (Spain); IPL (India)
• Ship prefixes: HMS, USS and RMS
• State postal abbreviations: NSW, QLD, VIC and TAS (Australia)

History and origins

The exact phrase three-letter acronym appeared in the literature in 1975.^[1] Three-letter acronyms were used as mnemonics in biological sciences,^[2] and their practical advantage was promoted by Weber in 1982.^[3] They are used in many other fields, but the term TLA is particularly associated with computing.^[4] The specific generation of three-letter acronyms in computing was mentioned in a JPL report of 1982.^[5]

In 1980, the manual for the Sinclair ZX81 home computer used and explained TLA.^[6] In 1988, in a paper titled "On the cruelty of really teaching computer science", eminent computer scientist Edsger W. Dijkstra wrote "Because no endeavour is respectable these days without a TLA ..."^[7] By 1992 it was in a Microsoft handbook.^[8]

Use of "TLA" spread through both industry and academia, and it has now become a generally understood initialism.

Combinatorics

The number of possible three-letter abbreviations (or permutations) using the 26 letters of the alphabet from A to Z (AAA, AAB ... to ZZY, ZZZ) is 26 × 26 × 26 = 17,576. Another 26 × 26 × 10 = 6760 can be produced if the third element is allowed to be a digit 0-9, giving a total of 24,336.

In English, WWW is the longest possible TLA to pronounce, typically requiring nine syllables. The usefulness of TLAs typically comes from how it is quicker to say the acronym instead of than the phrase they represent, however saying 'WWW' in English requires three times as many syllables than the phrase it is meant to abbreviate (World Wide Web). Consequently, "www" is sometimes abbreviated as "dubdubdub" in speech.^[9]

References in popular culture

• As early as 1967, the musical Hair included the song "Initials", whose final verse consisted only of TLAs, viz: "LBJ IRT USA LSD. LSD LBJ FBI CIA. FBI CIA LSD LBJ."
• In 1986, Will Shatter of the band Flipper formed a band named "Any Three Initials" (A3I), as a parody of the preponderance of hardcore punk bands with three-initial names.
• In 1998, the British band Love and Rockets released their last album, Lift, featuring the song "R.I.P. 20 C." that, apart from the refrain, consists only of three-letter abbreviations. A contest was held rewarding the first person to correctly give the meanings of all 69 of them.
• In 1999, German hip-hop group Die Fantastischen Vier (The Fantastic Four) released the song "MfG" ("Mit freundlichen Grüßen", German for "Best regards", literally "With friendly greetings"), also mainly consisting of TLAs.^[10]
• In 1999, the author Douglas Adams remarked: "The World Wide Web is the only thing I know of whose shortened form takes three times longer to say than what it's short for."^[11]
• In 2001, Portland Oregon songwriter Craig Carothers produced a song entitled "BFD" which includes many three-letter acronyms throughout the lyrics. It has been recorded by Carothers as well as Kathy Mattea, Berkley Hart and Don Henry.
• According to the Jargon File, a journalist once asked hacker Paul Boutin what he thought the biggest problem in computing in the 1990s would be. Paul's straight-faced response was: "There are only 17,000 three-letter acronyms."
• The Jargon File also mentions the abbreviation "ETLA" for "extended three-letter acronym" to refer to four-letter acronyms/abbreviations. "Extended three-letter acronym" is sometimes abbreviated to "XTLA".
• A Harvard University improv team is named Three Letter Acronym.
• On April 1, 2009, RFC 5513 standardized usage of TLAs for the Internet, including provisions for an IANA registry.

See also

Look up TLA in Wiktionary, the free dictionary.

• Four-letter abbreviation
• ISO 4217 (currency code)
• List of acronyms
• List of airports by IATA code
• List of all two-letter combinations
• List of computing and IT abbreviations
• List of IOC country codes
• List of three-letter broadcast callsigns in the United States
• Photographers' abbreviations
• Q code
• RAS syndrome
• Acronym

References