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