On Thursday, it appeared that Donald Trump had dropped a controversial and expensive provision of his tax plan, one that would have helped millions of small business owners as well as the companies in Trump's own business empire. That was a reversal from just a few days earlier, when the Republican presidential nominee had touted the provision on the campaign trail.

Now, it appears, Trump and his team are reinstating the provision. At least in part. Possibly in its entirety.

Confused? So are we.

Here's a quick timeline:

■ Before Thursday, Trump was proposing to tax income from all businesses, including so-called pass-through entities, at a 15 percent rate. Pass-throughs are a common small-business structure, and their profits are taxed at individual income tax rates. But the structure has become increasingly popular among some larger players, including financial firms and hundreds of Trump's own companies. For this reason, Democratic nominee Hillary Clinton had dubbed the proposed cut "the Trump Loophole."

■ In a speech Thursday, and fact sheets released initially by his campaign, Trump did not mention pass-throughs. He and his campaign appeared to restrict the 15 percent rate to traditional corporations, not pass-throughs. More important, his campaign instructed the economists at the independent Tax Foundation to assume pass-through income would still be taxed at individual rates, for the purposes of assessing the costs of Trump's plan to the federal budget.

■ That last distinction helped Trump get a lower cost estimate from the foundation: $4.4 trillion over 10 years, before effects on economic growth are factored in. With the pass-through cut included, Tax Foundation economists estimate, that cost would grow by at least $1 trillion.

■ Late Thursday, a leading small business group, the National Federation of Independent Business, praised Trump's plan. NFIB officials then told reporters they had been assured that Trump actually still planned to keep the cut for pass-throughs.

■ Also Thursday, the Trump campaign changed the language of its tax reform fact sheet posted online to include small businesses in the rate cut, but in a way that appeared to imply pass-throughs would, in fact, not be eligible for the cut.

■ On Friday, amid confusion, Trump economic adviser Stephen Moore responded to an email from The Washington Post to say that, yes, some pass-throughs would be eligible for the 15 percent rate. "The business has to be a legitimate business with employees," he wrote. For non-corporations — i.e., pass-throughs — profits "must be reinvested in the company and not taken out. 26 million small businesses will benefit."

That statement implies the cost of the plan would almost certainly grow, by a lot.

■ As of 2 p.m. Friday, Trump campaign officials had yet to clarify what, exactly, their plan would do for pass-throughs.

We will keep you posted.