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