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