18 CFR § 367.9
Prior period items
April 15, 2021
(a) Items of profit and loss related to the following must be accounted for as prior period adjustments and excluded from the determination of net income for the current year:
(1) Correction of an error in the financial statements of a prior year.
(2) Adjustments that result from realization of income tax benefits of pre-acquisition operating loss carry forwards of purchased subsidiaries.
(b) All other items of profit and loss recognized during the year must be included in the determination of net income for that year.