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