At (sign )
FUNCTION
The at sign (@) is used in email addresses to indicate a domain name or a social media account tag.
HISTORY
The origins of how and why the at sign was created and why it looks the way it does remain unclear. Allegedly, it has been created as a symbol to measure weight or quantity (to signify “at the rate of”) in some parts of Europe since the 14th century. That symbol looked more or less the same as the modern “at sign”: with a letter a circled by an elongated tail.
Since the use of email addresses, it is used to indicate at which domain name it is hosted.
DESIGN
The at sign is commonly designed as a lowercase a with a tail surrounding the letter. Due to the sign’s visual complexity, there are many solutions to simplify it by making the tail shorter (not entirely enclosing the a) or by starting the tail directly from the top instead of the bottom of the stem.
Notes
UNICODE
COMMERCIAL AT: U+0040