This specification covers sampling; inspection; rejection; certification; packaging and marking; and shipping, handling, and storage of gypsum panel products. When specified by the purchase agreement, samples of gypsum panel products shall be taken at the place of manufacture or at the destination. At least 0.25 % of the number of gypsum panel products in a shipment, but not less than three gypsum panel products, shall be so selected as to be representative of the shipment and shall constitute a sample for the purpose of tests by the purchaser or user. Inspection of the gypsum panel products shall be agreed upon between the purchaser and the producer or supplier as part of the purchase agreement. Rejection of gypsum panel products that fails to conform to the requirements specified shall be reported to the producer or supplier promptly and in writing. When specified in the purchase agreement, a producer's or supplier's report shall be furnished at the time of shipment certifying that the product is in compliance with the ASTM specification. Each gypsum panel product or package shall have legibly marked thereon the following: the thickness, the name of the producer or supplier, the brand name, if any, and the ASTM specification for the product. Gypsum panel products shall be shipped so as to be kept dry. Gypsum panel products shall be stored so as to be kept dry, preferably inside a building. Gypsum panel products shall be neatly stacked flat with care taken to prevent sagging or damage to edges, ends, and surfaces. Where necessary to store gypsum panel products outside, it shall be stacked flat, off the ground, supported on a level platform, and fully protected from weather and direct sunlight exposure.