In the rich text editor:
@obscurideer
In a comment:
[obscurideer](https://chowlings.com/user/obscurideer)
For Names and Avatars:
In the rich text editor:
%obscurideer
In a comment:
[](https://chowlings.com/user/obscurideer) [obscurideer](https://chowlings.com/user/obscurideer)