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