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