In the rich text editor:
@guroratz
In a comment:
[guroratz](https://chowlings.com/user/guroratz)
For Names and Avatars:
In the rich text editor:
%guroratz
In a comment:
[![guroratz's Avatar](https://chowlings.com/images/avatars/850.jpg?v=1644063334)](https://chowlings.com/user/guroratz) [guroratz](https://chowlings.com/user/guroratz)