In order to conform to the reporting requirements of the Securities Exchange Act of 1934 (15 U.S.C. § 78c et seq. (1971)), State banking institutions shall be permitted to accrete discount, by increasing book value not in excess of par value on obligations of the Federal Government, State or political subdivisions, and corporate obligations of investment grade purchased at a discount, by one of the following bookkeeping methods:
10 Pa. Code § 21.4