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