“CHECK-THE-BOX” rules will be tightened further. These rules let US taxpayers classify foreign subsidiaries as corporations, partnerships or “disregarded entities” simply by mailing a form to the IRS. Donald C. Lubick, the assistant Treasury secretary for tax policy, said in December, “We are now considering a series of transactions facililtated by check-the-box that we never foresaw nor intended, and that may give rise to results inconsistent with the purposes of the statutes they seek to exploit. We are currently determining how best to address them.”