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