Developer Donald Trump displays a copy of his net worth during his announcement that he will seek the Republican nomination for president, Tuesday, June 16, 2015, in the lobby of Trump Tower in New York. (AP Photo/Richard Drew)

When he announced that he was finally, actually running for president, Donald Trump held up a sheet of paper that outlined how much he was worth. "I have assets," he said, clenching a sheet compiled by a "big accounting firm, one of the most highly respected," of "9 billion, 240 million dollars." Less $500 million in debt, his net worth was a tidy, precise $8,737,540,000 (if you don't mind his accepting his contention that his "brand" and licensing was worth a third of that total).

That was on June 16. On Wednesday, less than a month later, he issued a press release stating that he'd filed a more detailed list with the Federal Election Commission. His net worth now, after being dropped by sponsors and battered in the press? $10 billion.

No, there's not a billion dollars in fast money to be found in anti-immigrant rhetoric. Trump claims that the difference stems from the real-estate valuations that he used in June being a year out-of-date. Then, the big accounting firm pegged the value of the properties he owned at about $4.3 billion. Since then, it's apparently jumped a billion dollars in value. (Which, to be fair, he vaguely alluded to in his speech.)

The line in Trump's release that has garnered the most -- completely justified -- snickering is the declaration that the FEC's report detailing income and assets "was not designed for a man of Mr. Trump‟s massive wealth." Un-humblebrag though it is, it is also demonstrably true. And that's why Trump's team was very careful to note that the new $10 billion figure comes from real estate. Because the vagueness of the form means that most of Trump's value will remain out of sight.

Here's Mitt Romney's disclosure from 2011, via the Center for Responsive Politics. (Trump's actual disclosure isn't yet available online.) Notice the highlighted categories for valuations. Anything worth $50 million or more simply gets flagged as "over $50 million." So if a building is worth, as Trump's press release suggested, $1.5 billion, it's listed as "over $50 million."

Notice that this always works in the other direction. If Trump's investment in a building is not worth $1.5 billion, but is instead worth, say, $50,000,001, it goes in the same category. Once the full form is released, Trump wants us to assume that he's worth far more than the sums displayed. One might as generously assume that he's not.

In light of his assertions about real estate, all of the other details he released today -- Trump getting $213 million from NBC for 14 seasons of "The Apprentice," and his $27 million in stock deals -- are peanuts. One not assumed to view his assertions generously might consider them a bit of hand-waving, a look-at-these-big-numbers move meant to be the focus of attention.

The FEC form was not designed for a man of Mr. Trump's willingness to assert massive wealth. He could eliminate any questions by releasing details of the precise valuations of his property using some other mechanism. But for Trump, that "over $50 million" loophole probably feels more than comfortable enough.

Real estate mogul and reality television star Donald Trump spoke about his personal wealth, China, Secretary of State John Kerry's bike accident and more in the top moments from his presidential announcement. (Sarah Parnass/The Washington Post)