49 Pa. Code § 11.28
A licensee may not express an opinion that financial statements are presented in conformity with GAAP if the financial statements contain any departure from GAAP that has a material effect on the financial statements taken as a whole, unless the licensee can demonstrate that by reason of unusual circumstances the financial statements would otherwise be misleading. In that case, the report of the licensee must describe the departure, the approximate effects thereof if practicable, and the reasons why compliance with the principle would result in a misleading statement. For purposes of this section, GAAP are considered to be defined by pronouncements issued by the Financial Accounting Standards Board and its predecessor entities and similar pronouncements issued by other entities having similar generally recognized authority.
49 Pa. Code § 11.28
The provisions of this §11.28 issued under section 506 of The Administrative Code of 1929 (71 P. S. § 186); and section 3(10)-(12) of The CPA Law (63 P. S. § 9.3(10)-(12)).
This section cited in 49 Pa. Code § 11.23 (relating to competence).