The White House has already promised to preserve all of President Donald Trump's tweets — even those he's deleted — but Democratic Rep. Mike Quigley of Illinois wants to make sure it follows through.

Quigley, who represents parts of Chicago, introduced the "Communications Over Various Feeds Electronically For Engagement" Act on Monday, designed to amend the Presidential Records Act to categorize social media posts as official presidential communications that must be preserved for posterity.

In case you didn't notice, the bill's acronym is COVFEFE — after the president's mysterious May 31 tweet (since deleted) reading: "Despite the constant negative press covfefe."

Trump later tweeted (and didn't delete): "Who can figure out the true meaning of 'covfefe' ??? Enjoy!" And White House Press Secretary Sean Spicer told a journalists at an off-camera briefing that day that "a small group of people know exactly what he meant."

Donald Trump on his mobile phone during a campaign stop in North Charleston, S.C., in February 2016. Matt Rourke / AP

Most observers believe Trump was simply misspelling the word "coverage."

"The name might be silly, but the issue's really important and serious," Quigley's spokeswoman, Tara Vales, told NBC News.

Like most matters presidential, Trump's use of Twitter is a subject of much controversy, especially after Spicer said last week that Trump's tweets should be regarded as official statements of policy.

On Monday, a three-judge panel of the 9th U.S. Circuit Court of Appeals took Spicer up on his offer. It cited Spicer's statement in its unanimous decision upholding a lower-court decision to block Trump's executive order to temporarily block entry into the United States by travelers from six mostly Muslim countries.

The court then went on to cite Trump's tweet last week declaring that "we need a TRAVEL BAN for certain DANGEROUS countries" as support for actually regarding the order as a blanket, and likely unconstitutional, "travel ban."

That's right, we need a TRAVEL BAN for certain DANGEROUS countries, not some politically correct term that won't help us protect our people! — Donald J. Trump (@realDonaldTrump) June 6, 2017

In April, the National Archives, which in 2014 declared that presidential social media posts should be handled as official documents, said it had been reassured by the White House that it's saving all of Trump's tweets.

But it remains unclear whether that policy applies to his personal account, @realDonaldTrump, in addition to his official account, @POTUS. Quigley's COVFEFE ACT would make that interpretation federal law.

"Tweets are powerful, and the president must be held accountable for every post," Quigley said in a statement.

Related: President’s Twitter Account Should Not Block Users, First Amendment Lawyers Argue

More to the point, Vales told NBC News, Twitter is "where the president goes to make a lot of his public policy proposals."

"When the president deletes a tweet, it is the equivalent of him destroying a record," she said.

Quigley is co-chairman of the Congressional Transparency Caucus, and "he would hope that anyone committed to those principles" would be on board, regardless of party, she said.

'Tweets are powerful, and the president must be held accountable for every post,' said Rep. Mike Quigley, D-Illinois, the bill's sponsor. Bill Clark / CQ-Roll Call Inc. - file

The nonprofit journalism site ProPublica independently archives tweets deleted by hundreds of elected officials — including Trump. Its database shows that the president has deleted 19 tweets from @realDonaldTrump since he was inaugurated on Jan. 20.

The great majority of the deleted tweets are relatively innocuous messages that appear to have been killed and quickly replaced to correct spelling errors or to add links to relevant material. (For example, on May 12, Trump gnomically tweeted and then deleted the single word "we.")

But a handful have addressed contentious policy issues, raising questions about Trump's motive for deleting them. Most prominent was this tweet on May 4: "An honor to host President Mahmoud Abbas at the WH today. Hopefully, something terrific could come out it between the Palestinians & Israel."

That tweet stayed up for 13 hours before it was deleted, with no replacement.

It turns out that Quigley's congressional account, @RepMikeQuigley, has deleted seven tweets of its own this year — including one on Monday promoting the COVFEFE ACT. According to ProPublica's database, however, all were quickly replaced, apparently to correct misspellings and add links.

(ProPublica is an investigative partner of NBC News.)

And in case you were wondering, Vales was finally able to clear up a question that has plagued analysts and news readers since May 31.

According to Quigley, she said, it's pronounced "coe-FEFF-feh."