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