In the rich text editor:
@Flick3rz
In a comment:
[Flick3rz](https://chowlings.com/user/Flick3rz)
For Names and Avatars:
In the rich text editor:
%Flick3rz
In a comment:
[](https://chowlings.com/user/Flick3rz) [Flick3rz](https://chowlings.com/user/Flick3rz)