In the rich text editor:
@Avi
In a comment:
[Avi](https://chowlings.com/user/Avi)
For Names and Avatars:
In the rich text editor:
%Avi
In a comment:
[![Avi's Avatar](https://chowlings.com/images/avatars/378.jpeg?v=1655944450)](https://chowlings.com/user/Avi) [Avi](https://chowlings.com/user/Avi)