In the rich text editor:
@robin
In a comment:
[robin](https://chowlings.com/user/robin)
For Names and Avatars:
In the rich text editor:
%robin
In a comment:
[![robin's Avatar](https://chowlings.com/images/avatars/709.png?v=1644063322)](https://chowlings.com/user/robin) [robin](https://chowlings.com/user/robin)