In the rich text editor:
@Noir
In a comment:
[Noir](https://chowlings.com/user/Noir)
For Names and Avatars:
In the rich text editor:
%Noir
In a comment:
[![Noir's Avatar](https://chowlings.com/images/avatars/421.jpg?v=1644063291)](https://chowlings.com/user/Noir) [Noir](https://chowlings.com/user/Noir)