I sync my status updates between Facebook, Twitter, MySpace, and Windows Live and in doing so, I sometimes get asked (especially from people who only use Facebook) what all of the symbols in my status updates mean. The two most common are @name and #HashTag.
@Name (also known as “at-replies”) are references to people or brands, specifically a Twitter alias. For example @YoungDems is a reference to http://twitter.com/YoungDems (the Young Democrats of America) or @WindowsLive is a reference to Windows Live. On Twitter, not only does @name become a hyperlink, but it shows-up on a user’s http://twitter.com/replies page:
#HashTags are single words that start with a “#” symbol which is often called a “Hash” and they are used to indicate not just use of that word but intent to tag the post with that keyword. Examples that I often use include “#tech” “#politics” and “#seattle.” Sometimes, hash tags can be multiple words merged together like “MoSoSo” for mobile social software or “SeaMayor” for the Seattle Mayor’s race. Has tags are also useful in that you can search for public tweets that contain a particular hash tag (ex: http://www.bing.com/twitter/search?q=%23seattle or http://twitter.com/#search?q=%23seattle)