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