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 United States, Canada, and in part Mexico and the Philippines), a three-hole standard is widely used. The holes are positioned symmetrically, with the centers apart. The diameter of the holes varies between manufacturers, with typical values being . The 5/16 value is most commonly used, as it allows for looser tolerances in both ring binder and paper punching. The distance of the hole center to the paper edge also varies, with being a typical value. Unlike ISO 838, this 3-hole system appears to have no well-established official specification, and is a de facto standard established by custom and tradition. It