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