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