In the rich text editor:
@fett
In a comment:
[fett](https://chowlings.com/user/fett)
For Names and Avatars:
In the rich text editor:
%fett
In a comment:
[![fett's Avatar](https://chowlings.com/images/avatars/1539.jpg?v=1674421203)](https://chowlings.com/user/fett) [fett](https://chowlings.com/user/fett)