In the rich text editor:
@Jammiistar
In a comment:
[Jammiistar](https://chowlings.com/user/Jammiistar)
For Names and Avatars:
In the rich text editor:
%Jammiistar
In a comment:
[](https://chowlings.com/user/Jammiistar) [Jammiistar](https://chowlings.com/user/Jammiistar)