In the rich text editor:
@KarinKitsune
In a comment:
[KarinKitsune](https://chowlings.com/user/KarinKitsune)
For Names and Avatars:
In the rich text editor:
%KarinKitsune
In a comment:
[![KarinKitsune's Avatar](https://chowlings.com/images/avatars/1453.jpg?v=1676934629)](https://chowlings.com/user/KarinKitsune) [KarinKitsune](https://chowlings.com/user/KarinKitsune)