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