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