C ompany MMY of China exported 1,000 fans to America. Partial shipments are not allowed according to the credit. However, when the seller made the shipment, he found 40 fans with broken package, some of the fan covers deformed and some switches off . The replacement was already too late. To ensure the quality of the goods, the shipper regarded that, according to “UCP 6 00”, even if partial shipments are not allowed, there is a tolerance of 5% of the quantity. He thought 40 fans were within the range of 5% of the whole quantity, so he shipped 960 fans actually. When the seller went to the bank with the documents for negotiation , the bank refused to negotiate. Question: What is the reason?