Etaoin shrdlu is a nonsense phrase that sometimes appeared in print in the days of "hot type" publishing because of a custom of type-casting machine operators to fill out and discard lines of type when an error was made. It appeared often enough to become part of newspaper lore - a documentary about the last issue of The New York Times composed using hot metal was titled Farewell, Etaoin Shrdlu - and "etaoin shrdlu" is listed in the Oxford English Dictionary and in the Random House Webster's Unabridged Dictionary. It is the approximate order of frequency of the 12 most commonly used letters in the English language.
History
The letters on type-casting machine keyboards were arranged by descending letter frequency to speed up the mechanical operation of the machine, so lower-case e-t-a-o-i-n and s-h-r-d-l-u were the first two columns on the left side of the keyboard. Each key would cause a brass 'matrix' from the corresponding slot in a font magazine to drop and be added to a line mold. After a line had been cast, the constituent matrices of its mold were returned to the font magazine. If a mistake was made, the line could theoretically be corrected by hand in the assembler area. However, manipulating the matrices by hand within the partially assembled line was time-consuming, threw an operator off their pace, and presented the chance of disturbing certain important adjustments. It was soon realized that it was much quicker to fill out the bad line and discard the resulting line of text, then redo it properly. To make the line long enough to proceed through the machine uninterrupted, operators would finish a faulty line by running a finger down the first columns of the keyboard, which also created a pattern that could be easily noticed by proofreaders. However occasionally such a line would be overlooked, and make its way into print.
Appearances outside typography
The phrase has gained enough notability to appear outside typography, including:
Computing
SHRDLU was used in 1972 by Terry Winograd as the name for an early artificial-intelligence system in Lisp.
The ETAOIN SHRDLU Chess Program was written by Garth Courtois, Jr. for the Nova 1200 mini-computer, competing in the 6th and 7th ACM North American Computer Chess Championship 1975 and 1976.
"Etienne Shrdlu" was used as the name of a character in Mavis Beacon Teaches Typing, touch-typing training software from the late 1980s.
Literature
Variations of Etaoin Shrdlu are used as character names in many works, including Elmer Rice's 1923 play The Adding Machine, Thomas Pynchon's early short storyThe Secret Integration, Max Shulman's 1944 book Barefoot Boy with Cheek, The Black Hole Travel Agency novels by Jack McKinney,
In 1942, Etaoin Shrdlu was the title of a short story by Fredric Brown about a sentient Linotype machine.
Anthony Armstrong's 1945 whimsical short story "Etaoin and Shrdlu" ends "And Sir Etaoin and Shrdlu married and lived so happily ever after that whenever you come across Etaoin's name even today it's generally followed by Shrdlu's".
Three pieces in The New Yorker magazine were published in 1925, under the pen name Etain Shrdlu. At least one piece in The New Yorker magazine had Etaoin Shrdlu in the title.
Douglas R. Hofstadter's Gödel, Escher, Bach: An Eternal Golden Braid includes a chapter named "SHRDLU, Toy of Man's Designing," which features a character named "Eta Oin" using a computer program "SHRDLU" — a reference to Terry Winograd's program and Bach's Jesu, Joy of Man's Desiring.
A series of books compiled by Denys Parsons comprised collections of humorous misprints and double meanings, mainly taken from newspapers. Parsons ascribed such errors to a mischievous character named Gobfrey Shrdlu, and referred to collectors of them as Shrdlologists.
Media
In 1958, the National Press Club published Shrdlu - An Affectionate Chronicle, a 50-year retrospective of the Club's history.
Etaoin Shrdlu is the name of a character in at least two Robert Crumb comic stories, and in the Pogo comic strips by Walt Kelly, "Mr. Shrdlu - Etaoin Shrdlu," is the name of a bookworm who criticizes Webster's Dictionary for, among other things, bad spelling.
Etaoin and Shrdlu both appear frequently in the drawings of Emile Mercier as place names, racehorses' names, and people's names.
Music
Shrdlu is listed as the composer of "Jam Blues", cut 1 on the 1951 Norman Granz-produced jazz album released in 1990 as Charlie Parker Jam Session. This appears to be a joke on Parker's part as Norman Shrdlu is credited in several Parker tunes.
"Etaoin Shrdlu" is the title of the first song on Cul de Sac's 1999 albumCrashes to Light, Minutes to Its Fall.
"Etaoin" and "Shrdlu", written and performed by Dallas Roberts, are original musical pieces created for the soundtrack of the US television series House of Cards, Season 2, Episode 10.