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