What items should NOT be washed in the GSD820 dishwasher?

Iron, pewter, tin, and wood should never be washed in the dishwasher, as they will rust, tarnish, or warp. Non-dishwasher items such as electronic air cleaner filters, furnace filters, and paint brushes should also never be washed, as they can damage the dishwasher and cause discoloration. Plastic items not marked 'dishwasher safe' should be checked with the manufacturer before washing. (Page 10)