In the rich text editor:
@Freak7F0x
In a comment:
[Freak7F0x](https://chowlings.com/user/Freak7F0x)
For Names and Avatars:
In the rich text editor:
%Freak7F0x
In a comment:
[![Freak7F0x's Avatar](https://chowlings.com/images/avatars/default.jpg)](https://chowlings.com/user/Freak7F0x) [Freak7F0x](https://chowlings.com/user/Freak7F0x)