Suppose I ask a question..I know that some user might be knowing its answer..

For eg,its a question related to a script.and i know that user xyz is good in scripts.I want him to notice my question..or rather I know he can answer..

By existing means,i can share a link to fb,twitter,email.But there is no option to share it with an ask ubuntu user itself.I dont know his e-id,m not on fb and twitter..or he isnt.

How can i do it?As of now i just add a comment with @username to let him know..any propper way to do it?