For purposes of this subchapter, the term “core qualifying activities” means activities in operating qualifying vessels in United States foreign trade.
The term “qualifying secondary activities” means secondary activities but only to the extent that, without regard to this subchapter, the gross income derived by such corporation from such activities does not exceed 20 percent of the gross income derived by the corporation from its core qualifying activities.
In the case of an electing group, subsections (c)(1) and (d)(3) shall be applied as if such group were 1 entity, and the limitations under such subsections shall be allocated among the corporations in such group.