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