American lumber standards, published as Simplified Practice Recommendation R 16-29, fourth edition, by the United States Department of Commerce, have been created for the purpose of eliminating unnecessary differences in the grading rules of the various softwood lumber manufacturers' associations of the United States and to embody the efforts to date of the several organized branches of the lumber trade to work out together such improvements in lumber manufacturing and merchandizing practice as will result in the maximum satisfaction in the use of lumber consistent with the price levels and the competitive conditions that characterize the lumber trade.