To indicate which method you're using to provide box content information, call CreateInboundShipment or UpdateInboundShipment and set the IntendedBoxContentsSource of the InboundShipmentHeader to one of the available options: NONE, FEED, or 2D_BARCODE. The default option is NONE. If the value of IntendedBoxContentSource is NONE at the time a shipment is confirmed, the manual processing fee will be assessed when the fulfillment center receives your inventory. If FEED or 2D_BARCODE is selected but box content information is not provided, your shipment will incur a manual processing fee.
For more information, see the Amazon MWS documentation and the forum announcement.
If your shipping processes do not support providing box content information, you can choose to skip this step and have Amazon manually process your shipment for a fee.