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400 - Invalid Contents Reference
The
invalid_contents_reference error code will be returned if you provide an invalid reference for shipment_contents. The shipment_contents reference format is sc_[0-9]{32}.This error code will be returned, for example, if you attempt to retrieve labels for shipment_contents but do not provide a valid reference for the contents:
GET /labels/sp_00982822462435387454701594214408/contents/sc_1234/zpl
In this example, the reference sc_1234 is not a valid reference for shipment_contents.