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