22 Pa. Code § 21.23
The provisions of this § 21.23 adopted October 2, 1970, effective October 3, 1970, 1 Pa.B. 324; amended October 6, 1972, effective October 7, 1972, 2 Pa.B. 1889; amended April 22, 1977, effective April 23, 1977, 7 Pa.B. 1084; reserved February 5, 1988, effective July 1, 1988, 18 Pa.B. 553. Immediately preceding text appears at serial page (98930).