How do you address a comment to a specific person?

Question

Just curious, does anyone know how to address comments to specific people in comments?

Answer 1

"@" + username
A.13S.

Answer 2

Adding to Slick's answer, the person whom you mention will get notified and just typing "@" and a suggestion list of people will pop-up and you can choose whom to address.

Answer 3

Slick and꧁༒Rishabh༒꧂
Thanks for your help!