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