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