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