From TestWiki

This template allows you to ping up to 4 users at once with out inserting a ":" so if you want to mention a user in the middle of a sentence you can just type {{Mention|Examknow|RhinosF1|Void|Southparkfan}} and it will output this: @Examknow, @RhinosF1 , @Void , @Southparkfan just make sure you sign it at the end of the comment like this: --~~~~. The system will not ping the user if you do not sign the comment