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