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