Don't forget Ireland, holder of many US corporate patents for some reason. Perhaps Apple can tell us why... Ireland has super low corporate taxes so Apple Ireland owns the IP, but they don't do anything, instead Apple licenses the IP from themselves for huge sums lowering their domestic profits, lowering total taxes, and increasing total after-tax profit.

And the Cayman islands and probably tons more less overt ways. Like housing, a ton of AirBnB places are actually just foreign investor properties used to hide/move money.