administrator first had such actual knowledge. (5) Joint regulatory authority Any temporary, proposed, or final regulation or other guidance of general applicability under this subsection shall be issued jointly by the Internal Revenue Service, Department of the Treasury, the Employee Benefits Security Administration, Department of Labor, and the Pension Benefit Guaranty Corporation. . (B) Conforming amendments Section 4050(a)(1) of the Employee Retirement Income Security Act of 1974 ( 29 U.S.C. 1350(a)(1) ) is amended— (i) in subparagraph (B)— (I) by striking provides and inserting “either— (i) provides