ETAOIN SHRDLU

Etaoin shrdlu (/ˈɛtiˌɔɪnˈʃɜːrdluː/ or /ˈeɪ.tɑːn.ʃrədˈluː/) 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. It appeared often enough to become part of newspaper lore, 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.

The letters on type-casting machine keyboards (such as Linotype and Intertype) were arranged by letter frequency, so e-t-a-o-i-n s-h-r-d-l-u were the lowercase keys in the first two vertical columns on the left side of the keyboard. When operators made a mistake in composing, they would often finish the line by running a finger down the first two columns of the keyboard and then start over. Occasionally the faulty line of hot-metal type would be overlooked and printed erroneously.

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