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