Section 3
SEC. 3. Officials whose salaries are fixed under Section one hereof and who, by virtue of their positions, hold or are designated under authority of law to hold positions or membership in other offices, boards, commissions, or instrumentalities of the National Government or in a private entity in representation of an agency or instrumentality of the National Government, shall not receive additional compensation and/or per diems, by reason of such position or membership in those other offices, boards, commissions, instrumentalities or private entities.