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