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