In the rich text editor:
@Sloompop
In a comment:
[Sloompop](https://chowlings.com/user/Sloompop)
For Names and Avatars:
In the rich text editor:
%Sloompop
In a comment:
[![Sloompop's Avatar](https://chowlings.com/images/avatars/618.png?v=1644063314)](https://chowlings.com/user/Sloompop) [Sloompop](https://chowlings.com/user/Sloompop)