A recursive acronym is an acronym that refers to itself, and appears 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.[1] Other references followed,[2] 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 a 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.
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 is the backronym "Mash Until No Good", which was created in 1960 to describe Mung, and revised to "Mung Until No Good". It lived on as a recursive command in the editing language TECO.[3] In 1977[3] programmer Ted Anderson coined TINT ("TINT Is Not TECO"), an editor for MagicSix. 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), in turn inspiring Anderson's retort SINE ("SINE is not EINE"). Richard Stallman followed with GNU (GNU's Not Unix).
Recursive acronym examples often 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.[4]
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 the tail recursive "Smart Programmers Are Required to Know SPARKS".[5]
Other examples are the YAML language, which stands for "YAML ain't markup language" and PHP language meaning "PHP: Hypertext Preprocessor".
HIJOS: Hijas e Hijos por la Identidad y la Justicia contra el Olvido y el Silencio[14] (literally, "Daughters and Sons for Identity and Justice against Forgetfulness and Silence")
HIM: HIM International Music, Taiwanese independent record label
The initials for the Commodore CDTV stand for Commodore Commodore Dynamic Total Vision.
TTP: a technology project in the Dilbert comic strip. The initials stand for "The TTP Project".[18]
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.
BOB: the primary antagonist from the series Twin Peaks. His name itself is an acronym standing for "Beware of BOB".
KOS-MOS: a character from the Xenosaga series of video games. "KOS-MOS" is a recursive acronym meaning "Kosmos Obey Strategical Multiple Operation System".
The GNU Hurd project is named with a mutually recursive acronym: "Hurd" stands for "Hird Unix-Replacing Daemons", and "Hird" stands for "Hurd Interfaces Representing Depth."
Jini claims the distinction of being the first recursive anti-acronym: 'Jini Is Not Initials'.[20][21] 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.
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,[citation needed] where the official meaning of an acronym is changed.
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.
According to Hayyim Vital, a 16th–17th century kabbalist, the Hebrew word adam (אדם, meaning "man") is an acronym for adam, dibbur, maaseh (man, speech, deed).[22]
According to Isaac Luria, a 16th-century kabbalist, the Hebrew word tzitzit (ציצת in its Biblical spelling, meaning "ritual fringes") is an acronym for tzaddik yafrid tzitziyotav tamid ("a righteous person should separate [the strings of] his tzitzit constantly").[23]