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