Beyond setting standards for Rhino 5, their other aim was to increase the compatibility between AutoCAD and Rhino. While CAD standards are normally only focused on AutoCAD, the new HDA CAD standards have been designed to work with Rhino 5 as much as possible.
Since HDA works with a broad range of clients and consultants around the world, they feel that it is in everyone's best interest to share CAD standards. To that end, they have made the latest version of their CAD standards available to everyone.
They would be delighted to get your feedback.