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