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