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