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