In the rich text editor:
@goopernooper
In a comment:
[goopernooper](https://www.worldofgaia.org/user/goopernooper)
For Names and Avatars:
In the rich text editor:
%goopernooper
In a comment:
[](https://www.worldofgaia.org/user/goopernooper) [goopernooper](https://www.worldofgaia.org/user/goopernooper)