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