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