© Evan VucciA Marine stands outside the West Wing of the White House, signifying President Donald Trump is in the Oval Office (Evan Vucci/AP)
President Donald Trump and president-elect Joe Biden are already breaking with tradition in failing to travel to the Capitol together for Wednesday's inauguration and it remains to be seen whether the outgoing president will leave a note in the Oval Office for its new occupant.
Previous presidential transitions have been marked with courtesy and sometimes humour, commodities in short supply during the 2020 tussle for the White House.
Mr Trump will already have departed Washington by the time his successor takes the reins but it is unclear whether the Resolute desk will have an envelope for Mr Biden to open in the departing president's familiar handwriting as the new commander-in-chief settles into the hotseat.
As he was preparing to leave the White House in January 1989, President Ronald Reagan wanted to leave a note for his successor, George HW Bush, and reached for a pad emblazoned with a cartoon by Sandra Boynton under the phrase, Don't Let the Turkeys Get You Down.
© Provided by PA MediaPresident Ronald Reagan is believed to be the first president to leave a note for his successor in the Oval Office (Dennis Cook/PA)
It featured a collection of turkeys scaling a prone elephant, the symbol of both men's Republican Party.
"Dear George, You'll have moments when you'll want to use this particular stationary. Well, go to it," Mr Reagan scrawled.
He noted treasuring "the memories we share" and said he would be praying for the new president before concluding: "I'll miss our Thursday lunches. Ron."
Thus was born the tradition of departing presidents leaving a handwritten note in the Oval Office for their successors.
The missives' contents start off as confidential, but are often eventually made public by archivists, references in presidential memoirs or via social media after journalists and others filed requests to obtain them.
The 32-year tradition is in peril this year.
Mr Trump has refused to accept the results of November's election and vowed not to attend Mr Biden's inauguration with Mr Biden saying he agreed with that decision.
That makes it doubtful Mr Trump will leave behind any handwritten, friendly advice for Mr Biden.
Presidents often write reflectively at the end of their time in office, including George Washington, who stated that he was "tired of public life" in recording why he was not seeking a third presidential term.
© Provided by PA MediaMelania Trump, left, and President Donald Trump, centre, remain on stage as Democratic presidential candidate former Vice President Joe Biden, right, walk away at the conclusion of the second and final presidential debate at Belmont University in Nashville, Tennesse (Julio Cortez/AP)
But historians say Mr Reagan's is likely the first instance of a personal letter being passed between presidents as they left and entered office.
"It was a sort of a revelation that a note like this was left," said Jim Bendat, author of Democracy's Big Day: The Inauguration Of Our President.
"We've come to expect them. It's a great tradition. It's one of those new traditions.
"And the traditions for Inauguration Day are like that - they often evolve through the years."
The notes are striking in their simplicity given just how big the job of the presidency is.
But they are also notable in their camaraderie and common purpose - especially since the handoff of power is often an unhappy one: Mr Reagan to Mr Bush was the last time the country had one president from the same party succeed another.
Despite losing to Bill Clinton in the bitter 1992 election, Mr Bush followed Mr Reagan's lead, this time on more stately, White House stationary.
"I leave a note on the desk for Bill Clinton. It looks a little lonely sitting there," Mr Bush recalled in his book All The Best, George Bush: My Life In Letters And Other Writings.
"When I walked into this office just now I felt the same sense of wonder and respect that I felt four years ago.
"I know you will feel that, too," Mr Bush wrote in the note, adding, "I wish you great happiness here.
"I never felt the loneliness some presidents have described."
He continued: "I'm not a very good one to give advice; but just don't let the critics discourage you or push you off course," before concluding: "Your success now is our country's success. I am rooting hard for you. Good luck - George."
Those words were so touching that the new president's wife, Hillary, later recalled they made her cry.
© Provided by PA MediaBill Clinton (Victoria Jones/PA)
"It speaks not only to his grace, but ultimately what the presidency should be all about, which is thinking about your country first," said Mark K. Updegrove, a historian and chief executive of the Lyndon Baines Johnson Foundation, who has written about the Bush family.
"Though he had been soundly defeated by Bill Clinton, George HW Bush, as a good American, was wishing the new president well."
Writing to that president's son, incoming President George W. Bush in 2000, Mr Clinton noted that the "burdens you now shoulder are great but often exaggerated" and that the "sheer joy of doing what you believe is right is inexpressible".
© Provided by PA MediaUS First Lady Michelle Obama and her two daughters Malia Ann (right) and Sasha who received a note from George W. Bush's daughters (Julien Behal/AP)
In his own letter to President Barack Obama eight years later, the younger Mr Bush advised that "critics will rage. Your 'friends' will disappoint you", but "no matter what comes, you will be inspired by the character and compassion of the people you now lead".
Mr Bush's twin daughters, Jenna and Barbara, were 27 at the time.
They wrote a sort of children's guide to the White House for Malia and Sasha Obama, then 10 and seven.
It included such advice as "slide down the banister of the solarium" and "when your dad throws out the first pitch for the Yankees, go to the game".
In his letter to Mr Trump in 2017, Mr Obama wrote: "This is a unique office, without a clear blueprint for success, so I don't know that any advice from me will be particularly helpful."
© Provided by PA MediaDonald Trump will not be present when Joe Biden takes the oath of office (Patrick Semansky/AP)
But Mr Obama did offer some words that now appear prophetic given Mr Trump's impeachment for inciting the deadly mob violence at the US Capitol.
"We are just temporary occupants of this office," he wrote.
"That makes us guardians of those democratic institutions and traditions - like rule of law, separation of powers, equal protection and civil liberties - that our forebears fought and bled for."
"It's up to us to leave those instruments of our democracy at least as strong as we found them," Mr Obama continued.
Mr Updegrove said even if the note tradition stops with Mr Trump, it could easily start again when Mr Biden leaves office.
He has already been vice president and spent 36 years in the Senate, where tradition and bipartisan congeniality are strong.
"There's no doubt in my mind that he would do it graciously," Mr Updegrove said.