Although it took 30 years, the IRS has issued a correction to a regulation dealing with attribution rules for purposes of determining a “brother-sister group” under IRC §52.  In TD 8179 the IRS changes a reference from “Reg. §1.414(c)-4(b)(1)” to “Reg. §1.414-4.”  And it’s the sort of quirky flaw that only tax geeks can love—and potentially exploit for the (temporary) benefit of eligible clients.