In the rich text editor:
@paeon
In a comment:
[paeon](https://chowlings.com/user/paeon)
For Names and Avatars:
In the rich text editor:
%paeon
In a comment:
[![paeon's Avatar](https://chowlings.com/images/avatars/903.jpg?v=1644063339)](https://chowlings.com/user/paeon) [paeon](https://chowlings.com/user/paeon)