Alan Tromer, vice-president of D, began filling out a purchase order for five different kinds of labels which D desired to buy from P. In handwriting he filled in the blank spaces for four different types of labels and in the quantity column he noted opposite each of the four orders '2M.' He described the fifth label as 'Label as Attached,' attached the copy of the desired label, and in the quantity column wrote '4MM.' The purchase order required delivery 'At Once,' and that shipment be by 'P.P.' or parcel post. In the lower left-hand corner of the purchase order there was printed in red letters: IMPORTANT: Above order number must appear on all correspondence, invoices, packages, and shipping papers. Notify us immediately if you are unable to ship complete order by date specified. Your acceptance of this order is your warranty to us that you are complying with the U.S. Fair Labor Standards Act of 1938, as amended, and we reserve the right to refuse merchandise, not in strict accordance with this order. P's representative received D's order by mail on February 26, 1968, examined it and filled out two company orders. The first four items, each for '2M,' were carried in stock and could promptly be shipped, so he placed them on one company order. The order for '4MM' other labels required special printing and wrote out the company order as '4000M' in place of '4MM' as used in D's purchase order. Labels were priced at $.67 per unit of one thousand and he wanted to show the number of units to the billing department. He also changed the method of delivery from parcel post to 'Best Way.' In order to ship the four million labels, weighing 622 pounds, by parcel post the shipment would have to be split up into twenty-pound allotments. He then sent a short letter of thanks to D to which he attached the yellow copy of the company order. D denied having ever received the letter. On April 10, 1968, the four million labels were delivered to D via motor freight. Alan Tromer refused the shipment and immediately called P, claiming that 'a terrible mistake had been made.' P sued D for payment. The jury found the term 'MM' by custom and usage in the trade means one million. It found that P's method of shipping was in substantial compliance with the purchase order; the reasonable value of the labels shipped to D was $2,680, and reasonable attorney fees for representing P were $750. D appealed. The court of civil appeals reversed the judgment on the trial court's refusal to submit an issue which inquired whether P should have known of D's error in preparing the purchase order. P appealed.