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