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