In the rich text editor:
@uqern
In a comment:
[uqern](https://chowlings.com/user/uqern)
For Names and Avatars:
In the rich text editor:
%uqern
In a comment:
[![uqern's Avatar](https://chowlings.com/images/avatars/default.jpg)](https://chowlings.com/user/uqern) [uqern](https://chowlings.com/user/uqern)