Yes. There is a threshold said to be 80% and above. I did not mean to agree with Nick's statement as the issue was grammatical not financial.
It is not discussed often or well that the US Government treats the GSEs in the US Budget in different ways. The Congressional Budget Office (CBO) has something of the GSEs on the books for its estimation purposes (costs, etc) and the Administration Office of Management and Budget (OMB) claims it does not.
What I have not been able to find is the IRS rule for 79.9% as not meeting a threshold for ...or description as GAAP. I found only references to noncontrolling interest, subsidiaries, consolidation, etc.