Does "@Username with spaces" work? Because the parser cannot know how many chars after the @ build the user name... I'll just test if "@[Barbie]" will work.
(Reason for my post: in this post "Editor Dave" was referenced with "@".)
[New feature] User mention notifications
Re: [New feature] User mention notifications
"Multiple exclamation marks," he went on, shaking his head, "are a sure sign of a diseased mind." --Terry Pratchett