Hi Jörg,
The code in the feeder system is designed to transfer only the highest-level Handling Units to GTS. If your Delivery is packed in Cartons that are then packed into Pallets, then only the Pallets will be transferred.
Since the system was specifically built to support ATLAS, then I guess that meets the requirements of German Customs. And it would also meet the requirements of most other European Customs authorities, as far as I know. Officers would always want to know about the packages they can actually see, without having to unpack anything.
Why do you want to report the Cartons instead?
Regards,
Dave