1. [common] The perforated edge strips
on printer paper, after they have been separated from the printed
portion. Also called selvage, perf, and ripoff
2. obs. The confetti-like paper bits punched out of cards or
paper tape; this has also been called `chaff', `computer
confetti', and `keypunch droppings'. It's reported that this was
very old Army slang, and it may now be mainstream; it has been
reported seen (1993) in directions for a card-based voting machine
in California.
Historical note: One correspondent believes `chad' (sense 2)
derives from the Chadless keypunch (named for its inventor), which
cut little u-shaped tabs in the card to make a hole when the tab
folded back, rather than punching out a circle/rectangle; it was
clear that if the Chadless keypunch didn't make them, then the
stuff that other keypunches made had to be `chad'. There is a
legend that the word was originally acronymic, standing for
"Card Hole Aggregate Debris", but this has all the earmarks of
a backronym.