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