In the rich text editor:
@Gus
In a comment:
[Gus](https://chowlings.com/user/Gus)
For Names and Avatars:
In the rich text editor:
%Gus
In a comment:
[![Gus's Avatar](https://chowlings.com/images/avatars/1021.PNG?v=1673723307)](https://chowlings.com/user/Gus) [Gus](https://chowlings.com/user/Gus)