Hemp cordage, report to the President on differences in costs of production of cordage, including cables, tarred or untarred, composed of 3 or more strands, each strand composed of 2 or more yarns, wholly or in chief value of hemp, in United States and in principal competing country, as ascertained pursuant to provisions of sec. 336 of title 3 of tariff act of 1930; with appendix, proclamation by the President.