In the rich text editor:
@kokokat123
In a comment:
[kokokat123](https://www.whistlercrest.com/user/kokokat123)
For Names and Avatars:
In the rich text editor:
%kokokat123
In a comment:
[](https://www.whistlercrest.com/user/kokokat123) [kokokat123](https://www.whistlercrest.com/user/kokokat123)