In the rich text editor:
@gizm0sz
In a comment:
[gizm0sz](https://chowlings.com/user/gizm0sz)
For Names and Avatars:
In the rich text editor:
%gizm0sz
In a comment:
[![gizm0sz's Avatar](https://chowlings.com/images/avatars/default.jpg)](https://chowlings.com/user/gizm0sz) [gizm0sz](https://chowlings.com/user/gizm0sz)