Thread:Project:Support desk/Can anyone design a new user talk system contain @username founction?/reply

So you want that all usernames - like they do on Twitter - start with an "@" sign? That is possible. MediaWiki has many hooks; have a look at the list of hooks and take that one, which is executed directly before a new user account is added to the database.

Then use the data, which you can access in this hook (this should be data about the new user, which should be added) and manipulate the username, so that it begins with an "@" sign.