; or (4) obligations fully guaranteed as to principal and interest by the United States. (f) Assessment funds for Regional Initiatives (1) In general The order shall provide that not less than 50 percent of the assessments (less administration expenses) paid by a manufacturer shall be used to support research, education, and promotion programs and projects in support of the geographic region of the manufacturer. (2) Geographic regions The order shall provide for the following geographic regions: (A) Region I shall comprise Connecticut, Delaware, the District of Columbia, Maine, Maryland, Massachusetts, New Hampshire, New Jersey, New York, Pennsylvania, Rhode Island, Vermont, and West Virginia. (B) Region II shall comprise Alabama, Florida, Georgia, Mississippi, North Carolina, South Carolina, Tennessee, and Virginia. (C) Region III shall comprise Illinois, Indiana, Iowa, Kentucky, Michigan, Minnesota, Nebraska, North Dakota, Ohio, South Dakota, and Wisconsin. (D) Region IV shall comprise Arizona, Arkansas, Kansas, Louisiana, Missouri, New Mexico, Oklahoma, and Texas. (E) Region V shall comprise Alaska, California, Colorado, Hawaii, Idaho, Montana, Nevada, Oregon, Utah, Washington, and Wyoming. (3) Adjustment of geographic regions The order shall provide that the Secretary may, upon recommendation of the Board, modify the composition of the geographic regions described in paragraph (2) . 1307. Referenda (a) Initial Referendum (1) Referendum required During the 60-day period immediately preceding the proposed effective date of the order issued under section 1304, the Secretary shall conduct a referendum among manufacturers eligible under subsection (b)(2) subject to assessments under section 1306. (2) Approval of order needed The order shall become effective only if the Secretary determines that the order has been approved by a majority of manufacturers voting who also represent a majority of the machine cavities in operation of those manufacturers voting in the referendum. (b) Votes permitted (1) In general Each