The at-sign, @, normally read aloud as "at", also commonly called the at symbol or commercial at, and less commonly a wide range of other terms (such as the strudel), is originally an accounting and commercial invoice abbreviation meaning "at a rate of" (e.g. 7 widgets @ £2 = £14). It was not included on the keyboard of the earliest commercially successful typewriters, but was on at least one 1889 model and the very successful Underwood models from the "Underwood No. 5" in 1900 onward. It is now universally included on computer keyboards. The mark is encoded at .