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