I am verifying the answers generated by an automatic system to the following question: what is the @ sign called?
Suggested answer: Originally an accounting and commercial invoice abbreviation meaning "at the 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.
Should I validate this answer?
