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