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