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