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 paper. The centers of these holes are 80±0.5 mm apart and have a distance of 12±1 mm to the nearest edge of the paper. The holes are located symmetrically in relation to the axis of the sheet or document. Any paper format that is at least 100 mm high (e.g. ISO A7 and larger) can be filed using this system. A printed document with a margin of 20–25 mm will accommodate ISO 838 filing holes. A four-hole extension is also commonly used. The two middle holes are punched in accordance with ISO 838, and so paper punched with the four