In the rich text editor:
@Vikilgp
In a comment:
[Vikilgp](https://chowlings.com/user/Vikilgp)
For Names and Avatars:
In the rich text editor:
%Vikilgp
In a comment:
[![Vikilgp's Avatar](https://chowlings.com/images/avatars/default.jpg)](https://chowlings.com/user/Vikilgp) [Vikilgp](https://chowlings.com/user/Vikilgp)