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