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