In the rich text editor:
@Bat
In a comment:
[Bat](https://chowlings.com/user/Bat)
For Names and Avatars:
In the rich text editor:
%Bat
In a comment:
[![Bat's Avatar](https://chowlings.com/images/avatars/7.png?v=1644063321)](https://chowlings.com/user/Bat) [Bat](https://chowlings.com/user/Bat)