In what's been called 'an olive branch to Native Americans' whose ancestors were slaughtered by the influx of European pioneers looking for new lives on the continent in the 1800s, ex-President Barack Obama is to promote the Indian "How!" greeting used between various tribes, but which has now fallen into disuse.
The greeting 'How!' is an Anglicized version of the Lakota/Dakota term 'Háu!', which means 'Hello'.
It is performed by raising your right hand with the palm facing the person you are speaking to, and saying "How!" in a deep voice that, it's assumed, sounds the same as Big Chief Sitting Bull would have said it.
Said Mr. Obama:
"It sounds a bit like 'Howdy!', but without the 'dy!' at the end. It's also important to have a grave look on your face when saying it. The Native Americans never smiled, as can be seen from countless western movies."
The former president has been trying to improve relations with the descendants of the tribes that were placed on reservations, and hunted down almost out of existence.
However, some opponents to the scheme have said the hand raised in that fashion makes it resemble the 'familiar salute' that the Nazis used when greeting close aquaintances.
White House staff say that President Donald Trump, enjoying the last days of his presidency, has been seen practising the greeting in front of a mirror.