Chad (paper) device which will not punch a complete circle in the tape but, instead, will only cut approximately three-quarters of the circumference of a circle ... thereby leaving a movable, or hinged, lid of paper in the tape." In the "New Hacker's Dictionary", two unattributed and likely humorous derivations for "chad" are offered, a back-formation from a personal name "Chadless" and an acronym for "Card Hole Aggregate Debris". Other etymologies claim derivation from the Scottish name for river gravel, "chad", or the British slang for louse, "chat". When a chad is not fully detached, it is described by various terms corresponding
Hole punch holes can be filed in binders that are consistent with ISO 838. The two additional holes are located 80 mm above and below these. The use of two additional holes provides more stability. This extension is sometimes referred to as the "888" system, because of the three 8-cm gaps between the holes. Some 2-hole punches have an "888" marking on their paper guide, to assist punching all four holes into A4 paper. For USA Legal Size paper format [8½ by 14 inches (215 by 356 mm)] traditionally 4 holes has been used in the past and still in use today