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