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