In the rich text editor:
@KittyAndDinos
In a comment:
[KittyAndDinos](https://chowlings.com/user/KittyAndDinos)
For Names and Avatars:
In the rich text editor:
%KittyAndDinos
In a comment:
[![KittyAndDinos's Avatar](https://chowlings.com/images/avatars/default.jpg)](https://chowlings.com/user/KittyAndDinos) [KittyAndDinos](https://chowlings.com/user/KittyAndDinos)