An Act amending the act of July 2, 1986 (P. L. 318, No. 77), entitled "An act amending the act of March 4, 1971 (P. L. 6, No. 2), entitled 'An act relating to tax reform and State taxation by codifying and enumerating certain *** offenses and penalties,' further providing for the sales tax, the personal income tax, the corporate net income tax, the capital stock tax and the realty transfer tax; authorizing a local real estate transfer tax; and making repeals," making the exclusion from income of gain from the sale of a residence effective on January 1, 1987.