45 Pa.C.S. § 902

Each title or part of the code and each permanent supplement thereto shall contain a certificate by the Director of the Legislative Reference Bureau that such title or part or permanent supplement thereto contains all documents required pursuant to section 702 (relating to contents of Pennsylvania Code) to be codified therein officially filed for public inspection prior to the closing date of such permanent supplement, by the government unit or units to which such title or part relates, which certificate shall be conclusive evidence of such fact in the case of documents issued, prescribed or promulgated by an agency. If an agency discovers an omission in such title or part, such omission shall be governed by the provisions of section 901 (relating to official text of published documents).