PC.net

Mention

@	Copy
	Popularity	★ ★ ★ ★ ★  Popular
	Direction	Text (used as a shortcut)
	Added	March 3, 2012
Description: The at symbol (@) is used to mention another user within a Twitter post. It allows you to link to other users within your tweet using the following format: @username. When used as a "mention" tag, the at symbol is not considered an emoticon.

Emoticon Information from PC.net
https://pc.net/emoticons/mention