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