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