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