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