The at sign (@), also called the atmark, at symbol, or commercial at, is formally an abbreviation of the accounting and commercial invoice term 'at the rate of.' In recent years its meaning has changed to also mean 'at' in the sense of 'located at,' especially in email addresses. Increasingly, @ is also used as a prefix to user names (e.g., @username) on social websites such as Twitter to denote a link, attribution or indirect reference.
The History Of The @-Symbol.The Presurfer
