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