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