Apparently, it’s little microdots in the printed paper.
So the Secret Service can look at it, say “Ah, this was Epson 1234A, sold at Best Buy to Mr. Buttons on 1/1/21.”
It’s allegedly to stop counterfeiting.
Another thing I never get around to.
When are they going to stop illegals from expropriating billions of tax dollars?
Guess I need a Somalian version of Windows, they have been enjoying heaps of privacy.