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