In the rich text editor:
@EveningStar09
In a comment:
[EveningStar09](https://chowlings.com/user/EveningStar09)
For Names and Avatars:
In the rich text editor:
%EveningStar09
In a comment:
[![EveningStar09's Avatar](https://chowlings.com/images/avatars/default.jpg)](https://chowlings.com/user/EveningStar09) [EveningStar09](https://chowlings.com/user/EveningStar09)