A new book claims that Melania Trump’s infamous “I REALLY DON’T CARE, DO U?” jacket was actually a not-so-hidden message aimed at a single rival family member: Ivanka Trump.

“American Woman: The Transformation of the Modern First Lady, from Hillary Clinton to Jill Biden,” by New York Times White House correspondent Katie Rogers, documents an “internal power struggle” between the two after Donald Trump won the 2016 election, according to a copy obtained by the New York Post.

The two “were locked in a quiet competition for press coverage” at the time of the jacket incident, the book says, noting that Melania had taken to calling Ivanka “the princess.”

Former administration officials told Rogers that the “I REALLY DON’T CARE, DO U?” message on the coat ― which made headlines for days ― was part of that competition, and meant for Ivanka.

It’s not clear what, exactly, she was hoping to get across to Ivanka with the jacket. However, given that she wore the jacket on a trip to see migrant children at a detention facility, it was widely considered to be in poor taste.

She initially denied that the jacket had any meaning at all and insisted it had nothing to do with the migrant children.

“It’s a jacket,” said Stephanie Grisham, who was her spokesperson at the time. “There was no hidden message.”

Afterward, however, the then-first lady changed the story, claiming it was a message aimed at “the people and for the left-wing media who are criticizing me.”

The new book claims that shift was orchestrated by Donald Trump, who pulled both women into the Oval Office, “yelled at them” and told them that the cover story would be that the jacket was a message aimed at the media, according to The Daily Mail.