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