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