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