Three-letter acronym explained

A three-letter acronym (TLA), or three-letter abbreviation, is as the phrase suggests an abbreviation consisting of three letters. The abbreviation for TLA, TLA, has a special status among abbreviations and to some is humourous since abbreviations that are three-letters long are very common and TLA is, in fact, a TLA.

TLA is autological.

Most TLAs are initialisms (the initial letter of each word of a phrase), but most are not acronyms 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
• 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, and GNU
• Corporations: BMW, IBM, AMD, KFC and NEC
• Countries: SRI, USA, CAR, UAE, DRC, etc.
• Currency: USD, GBP, and CHF
• Famous people: SRK, FDR, JFK, MJK, MLK, OBL, RBG, RDJ, RFK, and RMS
• File extensions: JPG, PDF, and XLS
• Military and weaponry: BFR and RPG
• Musical groups: R.E.M., XTC, TLC, E.L.O., MC5, GBH, O.A.R., MDC, D.R.I., JFA
• Personal advertisements: SBM for Single Black Male, STR for Short Term Relationship
• Political Parties: BJP, CCP, GOP, and AAP
• Religion: LDS, SBC, and SDA
• Ship prefixes: 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 networks: ABC (Australia, U.S.), BBC (UK), CBC (Canada, Japan), and NHK (Japan)
• Three-letter agencies: CIA, FBI, 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.^[1] Three-letter acronyms were used as mnemonics in biological sciences, from 1977^[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] In 1980, the manual for the Sinclair ZX81 home computer used and explained TLA.^[5] The specific generation of three-letter acronyms in computing was mentioned in a JPL report of 1982.^[6] In 1988, in a paper titled "On the Cruelty of Really Teaching Computing Science", eminent computer scientist Edsger W. Dijkstra wrote (disparagingly), "No endeavour is respectable these days without a TLA"^[7] By 1992 it was in a Microsoft handbook.^[8]

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. An additional 26 × 26 × 10 = 6,760 can be produced for each single position allowed to be a digit 0-9, 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.^[9]

In standard English, WWW is the TLA whose pronunciation requires the most syllables—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.^[10]

See also

• Acronym
• Alphabet agencies
• ISO 4217 (currency code)
• List of abbreviations in photography
• List of computing and IT abbreviations
• List of three-letter broadcast call signs in the United States
• List of three-letter combinations having Wikipedia articles
• List of three-letter acronym disambiguation pages on Wikipedia
• Lists of acronyms
• Lists of airports by IATA and ICAO code
• Q code
• Recursive acronym
  • RAS syndrome

Notes and References

1. M. J. . Levy . Review of The Logic of Social Systems . . 81 . 3 . 1975 . 2777655 . 10.1086/226119 . 658 . The acronyms DSE and DNA have something in common: each is a three-letter acronym..
2. S. R. . Seavey . P. H. . Raven . 1977 . Chromosomal Differentiation and the Sources of the South American Species of Epilobium (Onagraceae) . Journal of Biogeography . 4 . 1 . 57 . 10.2307/3038128 . 3038128 . 1977JBiog...4...55S . All taxa indicated by three-letter acronyms with strains indicated by a fourth letter if necessary..
3. W. A. . Weber . 1982 . Mnemonic Three-Letter Acronyms for the Families of Vascular Plants: A Device for More Effective Herbarium Curation . Taxon . 31 . 1 . 74–88 . 1220592 . 10.2307/1220592.
4. K. D. . Nilsen . A. P. . Nilsen . 1995 . Literary Metaphors and Other Linguistic Innovations in Computer Language . The English Journal . 84 . 6 . 65–71 . 820897 . 10.2307/820897.
5. [Steve Vickers (academia)|Steven Vickers]
6. https://tmo.jpl.nasa.gov/progress_report/42-70/70R.PDF TDA Progress Report
7. https://www.cs.utexas.edu/~EWD/transcriptions/EWD10xx/EWD1036.html On the cruelty of really teaching computer science
8. Dan Gookin (1992) The Microsoft Guide to Optimizing Windows page 211
9. Barnett . Adrian . Doubleday . Zoe . 2020-07-23 . Rodgers . Peter . The growth of acronyms in the scientific literature . eLife . 9 . e60080 . 10.7554/eLife.60080 . free . 2050-084X . 7556863 . 32701448.
10. Web site: DigiSpeak: A Glossary of the New Lingo . May 2011 . bryn mawr alumnae bulletin . Bryn Mawr College Alumnae Association . August 14, 2016.