In the rich text editor:
@princess
In a comment:
[princess](https://chowlings.com/user/princess)
For Names and Avatars:
In the rich text editor:
%princess
In a comment:
[![princess's Avatar](https://chowlings.com/images/avatars/1071.png?v=1644063249)](https://chowlings.com/user/princess) [princess](https://chowlings.com/user/princess)