Great Britain, as the chief offender in trampling roughshod over American privileges of trade in war time, added to her manifold transgressions, in August, 1916, by placing further curbs on neutral trade with the Netherland Overseas Trust. Under a scheme to ration the neutral countries of Norway, Sweden, Denmark, and Holland--that is, restricting their imports to their estimated domestic needs--further licenses granted to British exporters to trade with these countries were discontinued. Here was a check on British exports for fear of the surplus reaching Germany through neutral channels. A check on American exports followed by Great Britain forbidding the Overseas Trust to accept further consignments of certain commodities from the United States for Holland, and by her refusal to grant letters of assurance safeguarding the delivery of American shipments destined for the three other countries. By these devices Great Britain controlled supplies to these countries at the source. The effect was that certain American consignments predestined for Holland were stopped altogether, while the shipping companies trading between the United States and Scandinavia could not take cargoes without British assurances of safe discharge at their ports of destination. The British official view was that excessive exports from Great Britain to these countries could not very well be forbidden while permitting them from the United States and other neutral sources. The veto had to be general to be effective. One measure passed by Congress, providing for the creation of a Shipping Board, empowered the Secretary of the Treasury to forbid clearance to any vessel whose owner or agents refused to accept consignments offered for transport abroad by an American citizen for reasons other than lack of space or inadaptability of the vessel to carry the cargo offered. Another measure, the Omnibus Revenue Law, made similar provisions in a more drastic form, aiming specifically at retaliation for the Allies' blacklist of German-American firms, and the various blockades and embargoes in operation against American products. It provided that the owners or agents of vessels affiliated with a belligerent engaged in a war to which the United States was not a party must neither discriminate in favor of nor against any citizen, product, or locality of the United States in accepting or refusing consignments on pain of clearance being refused.