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