In the rich text editor:
@Kabber
In a comment:
[Kabber](https://chowlings.com/user/Kabber)
For Names and Avatars:
In the rich text editor:
%Kabber
In a comment:
[![Kabber's Avatar](https://chowlings.com/images/avatars/55.png?v=1644063306)](https://chowlings.com/user/Kabber) [Kabber](https://chowlings.com/user/Kabber)