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