explain what this mean. SEC. 3. There is hereby levied a tax of 2 per centum on the gross dollar value of each business, commercial, and/or financial transaction done within the United States. The President of the United States is hereby empowered by Executive order to increase or decrease the 2 per centum tax by not more than 50 per centum, when in his discretion he deems it advisable, in order to adequately finance the said pension roll. This tax shall be levied in addition to any other Federal tax on goods or commodities. This tax so levied shall be paid by the seller once each calendar month, calculated on the seller's aggregate gross sales, in accordance with rules and regulations to be promulgated by the Secretary of the Treasury of the United States. (a) It is hereby provided in order to facilitate the collection of this tax that all sellers of goods, commodities, and commercial things of value shall obtain a license upon payment of a fee, the amount thereof to be fixed by the Secretary of the Treasury, who is empowered with full authority to use his discretion as to methods and means of collecting this tax