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