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