One of the most versatile profanities in the English language took center stage at the U.S. Supreme Court on Monday.

But the nine members of the court and the attorneys arguing the case managed to avoid saying the word — or the company name, FUCT, that is its phonetic equivalent — aloud during an hourlong conversation about whether to strike down a federal trademark law that lets the government refuse to register marks deemed immoral or scandalous.

The measure was the basis for the U.S. Patent and Trademark Office's rejection of Erik Brunetti's 2011 application to register his clothing brand's name, a move later upheld by the office's Trademark Trial and Appeal Board.

Afterward, Brunetti took his case to the U.S. Court of Appeals for the Federal Circuit, which found the federal government correctly deemed the mark (pronounced like the word "fucked") scandalous but said the law in question violates the Constitution's protection of freedom of speech.

In lieu of referring to Brunetti's clothing brand directly, Supreme Court justices and attorneys alike opted for euphemistic references on Monday or spoke broadly about profanities and sexually explicit material.

Malcolm Stewart, a lawyer with the Justice Department arguing for the Trump administration, referred to FUCT as the “equivalent of the profane past participle form of a well-known word of profanity and perhaps the paradigmatic word of profanity in our language.”

Chief Justice John Roberts, meanwhile, called it “the vulgar word at the heart of the case.”

But the motivation behind the name FUCT was not lost on at least some of the justices.

“Come on, be serious,” Justice Samuel Alito told John Sommer, who argued the case on behalf of Brunetti. “You know what he’s trying to say.”

The court seemed divided as to whether the provision at issue, which has been on the books for more than a century, violated Brunetti’s free speech rights.

Justice Stephen Breyer seemed particularly concerned a ruling in Brunetti’s favor would open the door for trademarks featuring racial slurs, which could then be displayed on advertisements on buses or newsstands.

“Very often, the word involved in your case and the racial slur is not viewpoint,” Breyer said. “It is used to insult somebody, rather like fighting words, or it’s used to call attention to yourself.”

But others on the nine-member court acknowledged the law was broad and applied inconsistently by the Patent and Trademark Office.

Some trademark applications, Justice Ruth Bader Ginsburg said, were turned down on dual grounds: because the marks were scandalous as well as because they resemble marks that are already registered.

“If the mark is already registered,” Ginsburg said, “then it’s not scandalous.”

The U.S. Patent and Trademark Office, for example, declined to register FUCT but allowed FCUK, an acronym for the U.K.-based clothing chain French Connection.

How, Justice Neil Gorsuch asked, is a “reasonable citizen” supposed to know how the government will treat their mark?

“Is it a flip of a coin?” he asked.

The wording of the statute is “very broad,” said Justice Elena Kagan, who suggested the dilemma could be addressed legislatively.

“If Congress wants to pass a statute that’s narrower, that’s focused on vulgarity or profanity, then Congress can do that,” she said.

The Trump administration argues that in refusing to approve trademark applications with scandalous or immoral material, the government is “protecting unwilling viewers from material that they find offensive.”

A ruling from the justices is expected by the end of June.