In the rich text editor:
@LightFortunae
In a comment:
[LightFortunae](https://chowlings.com/user/LightFortunae)
For Names and Avatars:
In the rich text editor:
%LightFortunae
In a comment:
[](https://chowlings.com/user/LightFortunae) [LightFortunae](https://chowlings.com/user/LightFortunae)