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