Officials at one of the United States' biggest health agencies have been told they can't use the words 'transgender', 'fetus' and 'diversity' in new documents.
The Washington Post reports seven words and phrases have been banned in all - the others are 'science-based', 'evidence-based', 'vulnerable' and 'entitlement'.
The order came directly from the Trump administration, a whistleblower from the Centers for Disease Control and Prevention (CDC) told the Post.
Rather than 'science-based' for example, CDC officials have been told to use base its recommendations on 'science in consideration with community standards and wishes'.
They were reportedly told of the ban late last week, and applies to official documents being prepared for next year's budget.
The whistleblower, an analyst for the CDC, told the Post the reaction at the meeting was "incredulous".
"It was very much, 'Are you serious? Are you kidding?'"
They told the paper none of the CDC staff could ever recall "pushback from an ideological standpoint" before.
The fact the ban covers seven words and phrases brought comparisons to comedian George Carlin's infamous 'Seven Words You Can Never Say on Television' piece - shit, piss, f**k, c**t, c**ksucker, mother**ker, and tits.
The Trump administration has moved to strip rights from transgender people, and has pulled the US from the Paris Agreement, questioning the science of climate change.
It's also looking at rolling back abortion rights, with Vice-President Mike Pence wanting the 1973 legislation that legalised abortion in the country "consigned to the ash heap of history where it belongs".
It's not clear why the ban has been issued. The Los Angeles Times said it could either be the Trump administration "stepping fully into Totalitarian Lite territory", or a clever ploy to "keep social conservatives from teeing off on specific programs when it comes time to slash funding".
Either way, critics of the move have been quick to label it "Orwellian".
"Such censorship is a direct blow at the essence of science: accurately describing the physical world around us," science writer and media commentator Gleb Tsipursky wrote in Scientific American magazine.
"Science is the best method that we as human beings have of figuring out the truth of reality, and wishing away the facts by trying to substitute them with 'alternative facts' will greatly impede scientific progress."
'Alternative facts' was a phrase coined by Trump spokeswoman Kellyanne Conway after photographs proved Donald Trump's inauguration crowd was nowhere near as large as Barack Obama's.
The Department of Health and Human Services, which oversees the CDC, told ABC News the Washington Post report was a "mischaracterisation", but didn't deny there was a ban, nor explain what was mischaracterised.
Republicans in Congress have proposed reducing the CDC's budget.