A central issue in the confirmation hearing of Todd Blanche, the acting attorney general, on Wednesday was the extraordinary protection from Internal Revenue Service investigations he granted President Trump.

That immunity was part of a deal orchestrated by the Justice Department to end the president’s lawsuit against the I.R.S. The other part of that deal, a $1.8 billion fund aimed at paying political allies of Mr. Trump, set off a political firestorm on Capitol Hill, where many Republicans demanded its end. Mr. Blanche has since said that the so-called “anti-weaponization” fund is dead.

But the audit protection remains. Democrats have excoriated it as a corrupt and illegal handout to Mr. Trump, who has aggressively avoided taxes and faced I.R.S. audits throughout his life. Some Republicans, including Senator John Cornyn of Texas, had questions about the audit provision, too.

Here’s an explanation of Mr. Blanche’s directive letting the president off the hook from the I.R.S.:

What does Mr. Blanche’s order say?

Mr. Blanche’s May 19 order, while just one page, is not straightforward, with its substance packed into a single rambling sentence that tax lawyers said was clearly not written by a practitioner.

But the upshot appears to be twofold. First, the I.R.S. has to drop any inquiries, whether civil audits or criminal investigations, it was pursuing into Mr. Trump, his family members, their companies or “affiliated individuals.” Second, the I.R.S. can’t start any new investigations into tax returns that this potentially large pool of people and companies has already filed.

That means that any tax maneuver the Trumps have already used, whether the I.R.S. was already auditing it or not, is now off limits. The agency typically has three years after someone files a tax return to assess more in taxes. So there are potential audits of Mr. Trump and his family that the I.R.S. could have initiated — claims that “could have been asserted,” in the language of Mr. Blanche’s order — that it is now not supposed to. But the next tax return that Mr. Trump files could, theoretically, still be eligible for an audit.