Alternative limitations.
(4) Alternative limitations. Alternative limitations apply for certain utilities, railroads, and airlines in determining the regular tax liability limitation and, for nonrefundable energy credit carrybacks to taxable years ending before October 1, 1978, the nonrefundable energy credit tax liability limitation. These alternative limitations do not apply in determining the energy tax liability limitation for a taxable year ending after October 1, 1978. The provisions listed below set forth the alternative limitations: