A recursive acronym is an acronym that refers to itself. 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 (Education for Particular Task) later morphed into "Eptification for Particular Task".
Recursive acronyms typically form backwardly: either an existing ordinary acronym is given a new explanation of what the letters stand for, or a name is turned into an acronym by giving the letters an explanation of what they stand for, in each case with the first letter standing recursively for the whole acronym.
Early computer-related examples
In computing, an early tradition in the hacker community (especially at MIT) was to choose acronyms and abbreviations that referred humorously to themselves or to other abbreviations. Perhaps the earliest example in this context – from 1960 – is the backronym "Mash Until No Good", which was created to describe Mung, and a while later was revised to "Mung Until No Good". It lived on as a recursive command in the editing language TECO. In 1977 or 1978 came TINT ("TINT Is Not TECO"), an editor for MagicSix written (and named) by Ted Anderson. This inspired the two MIT Lisp Machine editors called EINE ("EINE Is Not Emacs", German for one) and ZWEI ("ZWEI Was EINE Initially", German for two). These were followed by Richard Stallman's GNU (GNU's Not Unix). Many others also include negatives, such as denials that the thing defined is or resembles something else (which the thing defined does in fact resemble or is even derived from), to indicate that, despite the similarities, it was distinct from the program on which it was based.
An earlier example appears in a 1976 textbook on data structures, in which the pseudo-language SPARKS is used to define the algorithms discussed in the text. "SPARKS" is claimed to be a non-acronymic name, but "several cute ideas have been suggested" as expansions of the name. One of the suggestions is "Smart Programmers Are Required to Know SPARKS". (this example is tail recursive)
Some organizations have been named or renamed in this way:
BWIA — BWIA West Indies Airways (formerly British West Indian Airways)
FARM — Farm Animal Rights Movement
FALE — FALE Association of Locksport Enthusiasts
YAML — YAML Ain't Markup Language (initially "Yet Another Markup Language")
ZINC – ZINC Is Not Commercial
Zinf — Zinf Is Not FreeAmp
ZOMBIE - Zombie is Optical Measurement of Barcodes by In-situ Expressiona, a technique for analysis of individual cells
ZWEI — ZWEI Was EINE Initially (“eins” and “zwei” are German for “one” and “two” respectively)
TTP - a technology project in the Dilbert comic strip. The initials stand for "The TTP Project".
GRUNGE - defined by Homer Simpson in The Simpsons episode "That '90s Show" as "Guitar Rock Utilizing Nihilist Grunge Energy", another uncommon example of a recursive acronym whose recursive letter is neither the first nor the last letter.
KOS-MOS - a character from the Xenosaga series of video games. "KOS-MOS" is a recursive acronym meaning "Kosmos Obey Strategical Multiple Operating Systems". It's unclear if it counts as a true recursive acronym, however, as the Kosmos referred to in the acronym may simply be an alternate spelling of cosmos.
Mutually recursive or otherwise special
The GNU Hurd project is named with a mutually recursive acronym: "Hurd" stands for "Hird of Unix-Replacing Daemons", and "Hird" stands for "Hurd of Interfaces Representing Depth."
RPM, PHP, XBMC and YAML were originally conventional acronyms which were later redefined recursively. They are examples of, or may be referred to as, backronymization, where the official meaning of an acronym is changed.
Jini claims the distinction of being the first recursive anti-acronym: 'Jini Is Not Initials'. It might, however, be more properly termed an anti-backronym because the term "Jini" never stood for anything in the first place. The more recent "XNA", on the other hand, was deliberately designed that way.
Most recursive acronyms are recursive on the first letter, which is therefore an arbitrary choice, often selected for reasons of humour, ease of pronunciation, or consistency with an earlier acronym that used the same letters for different words, such as PHP, which now stands for "PHP: Hypertext Preprocessor", but was originally "Personal Home Page". However YOPY, "Your own personal YOPY" is recursive on the last letter.
A joke implying that the middle initial "B." in the name of Benoit B. Mandelbrot stands for "Benoit B. Mandelbrot" plays on the idea that fractals, which Mandelbrot studied, repeat themselves at smaller and smaller scales when examined closely.
RAS syndrome – Using an acronym followed by one of the words composing that acronym (Redundant Acronym Syndrome syndrome)
Self-reference – A sentence, idea or formula that refers to itself
Web Ontology Language – Family of knowledge representation languages, which intentionally uses the acronym "OWL"
^Askary, A.; Sanchez-Guardado, L.; Linton, J. M.; Chadly, D. M.; Budde, M. W.; Cai, L.; Lois, C.; Elowitz, M. B. (18 November 2019). "In situ readout of DNA barcodes and single base edits facilitated by in vitro transcription". Nature Biotechnology. 38 (1): 66–75. doi:10.1038/s41587-019-0299-4. PMC . PMID 31740838.