In the rich text editor:
@Goop4Brains
In a comment:
[Goop4Brains](https://chowlings.com/user/Goop4Brains)
For Names and Avatars:
In the rich text editor:
%Goop4Brains
In a comment:
[](https://chowlings.com/user/Goop4Brains) [Goop4Brains](https://chowlings.com/user/Goop4Brains)