A three-letter acronym (TLA), or three-letter abbreviation, is 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. and Mrs. are not three-letter acronyms, but "TLA" itself is a TLA (an example of an autological abbreviation).
Most three-letter abbreviations are not, strictly, acronyms, but rather initialisms: all the letters are pronounced as the names of letters, as in APA // AY-pee-AY. Some are true acronyms, pronounced as a word: as with computed axial tomography, for example, CAT is almost always pronounced as the animal's name ( // ) in "CAT scan". Even the initialisms are however considered three-letter acronyms, because that term appeared first in widespread use, and is overwhelmingly popular today.
The exact phrase three-letter acronym appeared in the sociology literature in 1975.Three-letter acronyms were used as mnemonics 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 home computer used and explained TLA. The specific generation of three-letter acronyms in computing was mentioned in a JPL report of 1982. 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" By 1992 it was in a Microsoft handbook.
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 = 6760 can be produced if the third position is allowed to be a digit 0-9, giving a total of 24,336.
In standard English, WWW is the TLA whose pronunciation requires the most syllables—typically nine. The usefulness of TLAs 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.
An abbreviation is a shortened form of a word or phrase, by any method. It may consist of a group of letters or words taken from the full version of the word or phrase; for example, the word abbreviation can itself be represented by the abbreviation abbr., abbrv., or abbrev.; NPO, for nil per (by) os (mouth) is an abbreviated medical instruction. It may also consist of initials only, a mixture of initials and words, or words or letters representing words in another language. Some types of abbreviations are acronyms or grammatical contractions or crasis.
Camel case is the practice of writing phrases without spaces or punctuation. It indicates the separation of words with a single capitalized letter, and the first word starting with either case. Common examples include "iPhone" and "eBay". It is also sometimes used in online usernames such as "johnSmith", and to make multi-word domain names more legible, for example in promoting "EasyWidgetCompany.com".
A recursive acronym is an acronym that refers to itself, and appear most frequently in computer programming. The term was first used in print in 1979 in Douglas Hofstadter's book Gödel, Escher, Bach: An Eternal Golden Braid, in which Hofstadter invents the acronym GOD, meaning "GOD Over Djinn", to help explain infinite series, and describes it as a recursive acronym. Other references followed, however the concept was used as early as 1968 in John Brunner's science fiction novel Stand on Zanzibar. In the story, the acronym EPT later morphed into "Eptification for Particular Task".
Lists of abbreviations contain abbreviations and acronyms in different languages and fields. They include Latin and English abbreviations and acronyms.
LOL, or lol, is an initialism for laughing out loud and a popular element of Internet slang. It was first used almost exclusively on Usenet, but has since become widespread in other forms of computer-mediated communication and even face-to-face communication. It is one of many initialisms for expressing bodily reactions, in particular laughter, as text, including initialisms for more emphatic expressions of laughter such as LMAO and ROFL or ROTFL. Other unrelated expansions include the now mostly obsolete "lots of luck" or "lots of love" used in letter-writing.
An acronym is a word or name formed from the initial components of a longer name or phrase. Acronyms are usually formed from the initial letters of words, as in NATO, but sometimes use syllables, as in Benelux. They can also be a mixture, as in radar.
Scribal abbreviations or sigla are abbreviations used by ancient and medieval scribes writing in various languages, including Latin, Greek, Old English and Old Norse. In modern manuscript editing sigla are the symbols used to indicate the source manuscript and to identify the copyists of a work.
Acronym Finder (AF) is a free, online, searchable dictionary and database of abbreviations and their meanings.
A numeronym is a number-based word. Most commonly, a numeronym is a word where a number is used to form an abbreviation. Pronouncing the letters and numbers may sound similar to the full word, as in "K9" for "canine, relating to dogs". Alternatively, letters between the first and last letters of a word may be replaced by a number representing the number of letters omitted, such as in "i18n" for "internationalization" where "18" stands in for the word's middle eighteen letters ("[i]nternationalizatio[n]"). Sometimes the last letter is also counted and omitted. These word shortenings are sometimes called alphanumeric acronyms, alphanumeric abbreviations, or numerical contractions.
A user error is an error made by the human user of a complex system, usually a computer system, in interacting with it. Although the term is sometimes used by human–computer interaction practitioners, the more formal human error term is used in the context of human reliability.
Law enforcement personnel use a large body of acronyms, abbreviations, codes and slang to provide quick concise descriptions of people, places, property and situations, in both spoken and written communication. These vary between countries and to a lesser extent regionally.
Gene nomenclature is the scientific naming of genes, the units of heredity in living organisms. It is also closely associated with protein nomenclature, as genes and the proteins they code for usually have similar nomenclature. An international committee published recommendations for genetic symbols and nomenclature in 1957. The need to develop formal guidelines for human gene names and symbols was recognized in the 1960s and full guidelines were issued in 1979. Several other genus-specific research communities have adopted nomenclature standards, as well, and have published them on the relevant model organism websites and in scientific journals, including the Trends in Genetics Genetic Nomenclature Guide. Scientists familiar with a particular gene family may work together to revise the nomenclature for the entire set of genes when new information becomes available. For many genes and their corresponding proteins, an assortment of alternate names is in use across the scientific literature and public biological databases, posing a challenge to effective organization and exchange of biological information. Standardization of nomenclature thus tries to achieve the benefits of vocabulary control and bibliographic control, although adherence is voluntary. The advent of the information age has brought gene ontology, which in some ways is a next step of gene nomenclature, because it aims to unify the representation of gene and gene product attributes across all species.
Abbreviations are a common part of the Hebrew language, with many organizations, places, people and concepts known by their abbreviations.
The articles in English are the definite article the and the indefinite articles a and an. The definite article is used when the speaker believes that the listener knows the identity of the noun's referent. The indefinite article is used when the speaker believes that the listener does not have to be told the identity of the referent. No article is used in some noun phrases.
The acronyms DSE and DNA have something in common: each is a three-letter acronym.
All taxa indicated by three-letter acronyms with strains indicated by a fourth letter if necessary.