Section, Pub. L. 91–510, title II, § 242(a), Oct. 26, 1970, 84 Stat. 1171, provided that each meeting conducted by Senate Committee on Appropriations be open to the public except when testimony to be taken might relate to a matter of national security, tend to reflect adversely on character or reputation of witness or other individual, or divulge matters deemed confidential under other provisions of law or regulations.