Tax provision expired after August 1, 1992

(1) Rules for allocation and apportionment of research expenses (sec. 864(f)); 2

Tax provisions expired after December 31, 1992

(1) Placed-in-service date for the nonconventional fuels production tax credit (sec. 29);

(2) Excise tax on certain vaccines for the Vaccine Injury Compensation Trust Fund (secs. 4131 and 9410).

(3) Top estate tax rate (55/53 percent) reduces to 50 percent (sec. 2001).

Statutory provision expired generally after the first 6 months of the taxpayer's first taxable

year beginning after August 1, 1991, but was extended by administrative action for 18 months.