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