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