<jargon, printer> /chad/ (Or "selvage" /sel'v*j/ (sewing and weaving), "perf", "perfory", "snaf"). 1. The perforated edge strips on paper for sprocket feed printers, after they have been separated from the printed portion.
The term perf may also refer to the perforations themselves, rather than the chad they produce when torn.
2. (Or "chaff", "computer confetti", "keypunch droppings") The confetti-like bits punched out of punched cards or paper tape which collected in the chad box.
One of the Jargon File's correspondents believed that "chad" derived from the chadless keypunch.