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