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