Not of global interest 

I made some serious edits to bring this article into line with current U.S. federal tax law.  The term "notional principal contract" is really just the U.S. tax term for "swap".  No one other than a U.S. tax professional really cares about this.  My edits were really just to prevent the article from trapping the unwary.  If someone else thought this article should be deleted outright, I would fully agree.