Executive Order 5666—Permitting Persons Holding Certain Positions to Receive Appointments Under the Department of Commerce
Executive Order No. 9 of January 17, 1873, prohibiting the holding of Federal and State offices at the same time, is hereby amended so as to permit persons holding State, Territorial, or municipal positions to receive, unless prohibited by law, appointments under the Department of Commerce when the Secretary of that department deems such employment necessary to secure a more efficient administration of the duties of his department.
The White House,
July 3, 1931.
Herbert Hoover, Executive Order 5666—Permitting Persons Holding Certain Positions to Receive Appointments Under the Department of Commerce Online by Gerhard Peters and John T. Woolley, The American Presidency Project https://www.presidency.ucsb.edu/node/361257