A three-letter acronym, three-letter abbreviation, or TLA is an acronym, alphabetism or initialism or an abbreviation, 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." or "Mrs." would not be described as three-letter acronyms.

Most three-letter abbreviations are initialisms i.e., all the letters are pronounced as letters, as in LSD. Very few fit the narrow strict definition of acronym which requires it to be pronounced as a single word, as in DOS, which is unusual in three-letter abbreviations.

When TLA is defined as three-letter abbreviation, then TLA has the self-referential feature that TLA is its own TLA. Note that when TLA is defined as three-letter acronym, this feature does not apply.

Contents 1 Examples 2 History and origins 3 Combinatorics 4 References in popular culture 5 See also 6 Footnotes 7 External links

[edit] Examples

• Countries: USA and UAE.
• Politicians: JFK and LBJ.
• Computer Terms: RAM, CPU and DOS.
• Corporations: IBM and NEC.
• Three Letter Agencies: CIA, FBI, FSB, SAS and SIS.
• Television networks: ABC (Aus., U.S.), BBC, CBC, etc.
• Personal advertisements: SBM for Single Black Male.
• Chemistry, biology, pharmaceuticals: MSG, GMO and LSD.
• Clinical medicine: CHF and CAD
• Communications shorthand: LOL and OMG.
• Military and weaponry: BFR and RPG
• Wars and political conflicts: WWI and HYW.
• ISO currency codes: USD, EUR, GBP and JPY
• IATA airport codes: SFO and LHR.
• Academic testing: SAT, ACT and GRE.
• Canine Registries: ACA and CKC
• Sports leagues: NFL, NBA, MLB, (all North America); AFL and NRL (Australia); NPB (Japan); ACB (Spain)
• Ship prefixs: HMS, USS, RMS, etc.

Wikipedia also has an exhaustive list of TLAs.

[edit] History and origins

The exact term three-letter acronyms 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 1988, in a paper titled "On the cruelty of really teaching computer science" In 1988, eminent computer scientist Edsger W. Dijkstra wrote "Because no endeavour is respectable these days without a TLA ..."^[6] By 1992 it was in a Microsoft handbook.^[7]

Use of "TLA" spread through both industry and academia, and it has now become a generally understood initialism.^[8] For a complete discussion of the various forms of abbreviations, acronyms and other letter substitutions, see Acronym and initialism.

[edit] 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. 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, requiring nine syllables. Although in written English it is an abbreviation, in spoken English it may use more syllables than that which it is abbreviating.^[9] See also Pronunciation of "www".

[edit] 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" (ATI), 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 regards"), 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 term "ETLA" for "Extended Three Letter Acronym" to refer to four letter acronyms/abbreviations. Also, "Extended Three Letter Acronym" is sometimes abbreviated to "XTLA".

[edit] See also

• Lists of TLAs
• Four-letter abbreviation
• ISO 4217 (currency code)
• List of acronyms and initialisms
• 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
• Q code
• RAS syndrome

[edit] Footnotes

[edit] External links

• Abbreviations.com — A directory and search engine for acronyms, initialisms, and other abbreviations.
• Acronymfinder.com — Resource to find multiple meanings of acronyms, sorted by type.
• TLA Wörterbuch - Casia TLA collection.
• GTF - the GPL'ed TLA FAQ.
• The Great Abbreviations Hunt - A TLA for every combination of letters.
• All Acronyms Dictionary — Database of acronyms with thousands of TLAs
• AuctionSlanguage.com - A resource to find meanings of acronyms and abbreviations used on auction sites. Includes many TLA's like NWT and HTF.