A new wrinkle in the story of Donald Trump’s avoidance of paying taxes for more than a decade: He reportedly used legally dubious maneuvers his own lawyers suggested the IRS would find improper if they were to audit him. According to The New York Times, the now-Republican presidential nominee avoided reporting hundreds of millions of dollars in taxable income using a strategy tax experts refer to as a “stock-for-debt swap,” relying heavily on mathematical trickery. In essence, given the timing of this tax strategy, Trump received enormous tax benefits for being in debt during an era in which his casinos suffered great losses. Congress and the IRS eventually banned “stock-for-debt” swaps by corporations in 1993, but Trump was likely able to circumvent the law by using partnerships. That method was later banned by Congress in 2004.