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