From the Wikipedia page 
Fictitious entries, also known as fake entries, Mountweazels, ghost words and nihil articles, are deliberately incorrect entries or articles in reference works such as dictionaries, encyclopedias, maps, and directories. Entries in reference works normally originate from a reliable external source, but no such source exists for a fictitious entry. Copyright trap is a specific case where the motivation for the entry is to detect plagiarism or copyright infringement.
The neologism Mountweazel was coined by the magazine, The New Yorker, based on a fictitious entry for Lillian Virginia Mountweazel in the 1975 edition of the New Columbia Encyclopedia. Another term, nihil article, is of uncertain origin first appearing on the German Wikipedia as Nihilartikel. It combines the Latin word nihil, "nothing" with German Artikel, "article".
Motivations for creationEdit
Besides the possibility of playful mischief, fictitious entries may be composed to catch copyright infringement. By including a trivial piece of false information in a larger work, it is easier to demonstrate plagiarism if the fictitious entry is copied along with other material. An admission of this motive appears in the preface to Chambers's 1964 mathematical tables: "those [errors] that are known to exist form an uncomfortable trap for any would-be plagiarist". This is very similar to the inclusion of one or more trap streets on a map or invented phone numbers in a telephone directory.
In the United States, they may be used to demonstrate copying, but are not always sufficient to prove legal infringement if the material was not eligible for copyright (see Feist v. Rural, Fred Worth lawsuit or Nester's Map & Guide Corp. v. Hagstrom Map Co., 796 F.Supp. 729, E.D.N.Y., 1992.) These traps may still aid in detection of copying and may be proof of copyright infringement if the original material was eligible for copyright.
An outright forgery intended to mislead the reader on a matter of substance would not generally be classed as a fictitious entry.
Most listings of the members of the German parliament feature the fictitious politician Jakob Maria Mierscheid, allegedly a member of the parliament since 1979. Among other activities he is reported to have contributed to a major symposium on the equally fictitious stone louse in Frankfurt.
The German-language Der neue Pauly. Enzyklopaedie der Antike, edited by H. Cancik and H. Schneider, vol. 1 (Stuttgart, 1996, ISBN 3-476-01470-3) includes a fictitious entry now well-known amongst classicists: a deadpan description of an entirely fictional Roman sport, apopudobalia, which resembles modern football (soccer).
Appletons' Cyclopædia of American Biography (1887-1889) contains about two hundred fictitious entries.
Zzxjoanw was the last entry in Rupert Hughes’ Music Lovers’ Encyclopedia of 1903, and it continued as an entry in subsequent editions down to the 1950s. It was identified as a Maori word for a drum. Later, it was proved to be a hoax (becoming suspect because Māori does not use the letters J, X or Z).
The 1975 New Columbia Encyclopedia contains a fictitious entry on Lillian Virginia Mountweazel (1942-1973). Her biography claims she was a fountain designer and photographer, best known for Flags Up!, a collection of photographs of rural American mailboxes. Supposedly she was born in Bangs, Ohio, and died in an explosion while on assignment for Combustibles magazine. Mountweazel was the subject of an exhibit in Dublin in March 2009 examining her fictitious life and works.
The first printing of the 1980 New Grove Dictionary of Music and Musicians contains two fictitious entries: on Guglielmo Baldini, a non-existent Italian composer, and Dag Henrik Esrum-Hellerup, who purportedly composed a small amount of music for flute. Esrum-Hellerup's surname derives from a Danish village and a suburb in Copenhagen. The two entries were removed from later editions, as well as from later printings of the 1980 edition.
In August 2005, The New Oxford American Dictionary gained media coverage when it was leaked that the second edition contained at least one fictional entry. This later was determined to be the word esquivalience, defined as "the wilful avoidance of one's official responsibilities," which had been added to the edition published in 2001. It was intended as a copyright trap, as the text of the book was distributed electronically and thus, very easy to copy.
The German-language medical encyclopedia Pschyrembel Klinisches Wörterbuch features an entry on the Steinlaus (stone louse), a rock-eating animal. The scientific name Petrophaga lorioti implies its origin: a creation of the German humorist Loriot. The Pschyrembel entry was removed in 1996 but, after reader protests, was restored the next year, with an extended section on the role of the stone louse in the fall of the Berlin Wall.
Joel Whitburn's pop chart research books say that Ralph Marterie's version of "The Song Of Love" peaked at #84 for the week ending December 26, 1955. However, Billboard Magazine did not put out an issue that week, and Marterie never recorded this tune. A similar situation occurs in his compilation of Billboard's Rock charts, where Whitburn includes the fictitious song "Drag You Down" by the equally non-existent group The Cysterz.
Fictitious entries on maps may be called phantom settlements, trap streets, paper towns, or other names. They are intended to serve as traps for identifying copyright infringements.
In 1978, the fictional Ohio towns of Goblu and Beatosu were inserted into that year's official state of Michigan map as nods to the University of Michigan and its traditional rival, Ohio State University.
The fictional town of Agloe, New York was invented by map makers, but eventually became identified as a real place by its county administration because a building, the Agloe General Store, was erected at its fictional location. The "town" is featured in the novel Paper Towns by John Green. A character in the book has a dog named Myrna Mountweazel.
Mount Richard, a fictitious peak on the continental divide in the United States, appeared on county maps in the early 1970s. It was believed to be the work of a draftsman, Richard Ciacci. The fiction was undiscovered for two years.
In the United Kingdom in 2001, the Ordnance Survey (OS) and the Automobile Association (The AA), a British motoring association, reached an out-of-court settlement of £20m after deliberate "errors" placed on OS maps were reproduced on maps by the AA. A portion of this sum was to cover missed and future royalty payments.
Trivia books, etc.Edit
The Trivia Encyclopedia placed deliberately false answers for a limited number of quiz questions, for copy-trap purposes; this was tested when the makers of Trivial Pursuit based some of their questions on the work.
The book The Golden Turkey Awards describes many bizarre and obscure films. The authors of the work state that one film described by the book is a complete hoax, and they challenge readers to spot the made-up film; the imaginary film was Dog of Norway, which supposedly starred "Muki the Wonder Dog", named for the authors' own dog.
The Urban Legends Reference Pages (snopes.com) include a section entitled The Repository of Lost Legends, containing false discussions of made-up legends (for example, that the bear in the design of the Flag of California is the result of a handwritten note being misread and that it was meant to be a pear). The aim of the stories in the section is to caution readers against using appeals to authority, and to encourage the checking of references for claims that seem unreasonable; the acronym for "The Repository of Lost Legends" spells out "troll". Within another of the Urban Legends Reference Pages, there are two records of entities who have fallen for the trap, one being the TV show Mostly True Stories: Urban Legends Revealed, and another on a trivia board game called Urban Myth.
Fictitious entries are sometimes plot points in fiction, including:
A Fred Saberhagen science fiction short story, "The Annihilation of Angkor Apeiron," in which an encyclopedia article for a star system was a fictitious entry included in the encyclopedia to detect plagiarism, which caused a ship to end up in an empty star system where it ran out of fuel and ceased to be a threat to humanity.
Jorge Louis Borges's Tlön, Uqbar, Orbis Tertius tells of an encyclopedia entry on what turns out to be the imaginary country of Uqbar. This leads the narrator to the equally fantastic region of Tlon, the setting for much of the country's literature.
Australian archaeologist Tim Flannery's book, Astonishing Animals, written in collaboration with painter Peter Schouten, describes some of the more outlandish animals alive on Earth. They caution that one of the animals is a product of their imagination and it is up to the reader to distinguish which one it is.
Rhinogradentia are a fictitious mammalian order, extensively documented in a series of articles and books by the equally fictitious German naturalist Harald Stümpke. Allegedly, both the animals and the scientist were the creations of Gerolf Steiner, a zoology professor at the University of Heidelberg.
Each issue of the product catalogue for Swedish consumer electronics and hobby articles retailer Teknikmagasinet contains a fictitious product. Finding that product is a contest, "Blufftävlingen", in which the best suggestion for another fictitious product from someone who spotted the product gets included in the next issue.
Muse (a magazine for children 10–14, published in the USA) regularly includes a two-page spread containing science and technology news. One of the news stories is false and readers are encouraged to guess which one.
Games (a magazine devoted to games and puzzles) used to include a fake advertisement in each issue.