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