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