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