In the rich text editor:
@Ghostie
In a comment:
[Ghostie](https://chowlings.com/user/Ghostie)
For Names and Avatars:
In the rich text editor:
%Ghostie
In a comment:
[![Ghostie's Avatar](https://chowlings.com/images/avatars/2490.png?v=1695686677)](https://chowlings.com/user/Ghostie) [Ghostie](https://chowlings.com/user/Ghostie)