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