Tomorrow's change of Oval Office occupants is a ritual full of traditions and customs.

One of the more modern ones began in 1989 when Ronald Reagan left a note for George H.W. Bush on stationary with a whimsical bit of advice.

Since then, the messages have often been heartfelt and written on more stayed White House stationary, like the one

Bush himself left for Bill Clinton, wishing him great happiness.

Lindsay Chervinsky is the executive director of the George Washington Presidential Library.

Lindsay, since Reagan left that note in 1989, by my count, there have been five of those notes.

Has there been a common theme?

Well, I think the theme in general is about patriotism, service, the importance of the office being bigger than one person, and sort of an inspirational encouragement for the next person in office.

How are they usually left? Are they handed to them or how does it, how does it work?

They're usually left on the desk. It's usually one of the last things the president does.

They'll usually write their successor's name and then leave it on the desk for them to find when

they come into the office for the first time.

And they come in the office for the first time after the inaugural ceremony, after they come down

Pennsylvania Avenue. Absolutely. One of the longer

ones was Barack Obama's for Donald Trump. It was Donald Trump said he found it so thoughtful that he even

called Obama to thank him for it. What did it say? Yeah, this letter is interesting because it's a little

bit more preachy than some of the other letters. It kind of reminds Trump of the challenges that some Americans face, that they are not all

as fortunate as Obama and Trump.

It reminds him about the importance of democratic norms and institutions and the office being

a symbol of that, not just being about Trump's political fortunes.

And it reminds him to enjoy his family

while he's in office because the job is a hard one. Sometimes these letters are not made public

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