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