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