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