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 the page. To prepare documents for comb binding there are special 19-hole punches for letter paper and 23-hole punches for A4 paper. The holes are usually rectangular in shape, to accommodate the plastic binding combs. Specialized punches are also used for the similar but incompatible coil binding process. There are office models available for the perforation of 1 to 150 sheets of paper, and industrial models for up to 470 sheets. Most multiple-hole and many single-hole punches accumulate the waste paper circles (chads) in a chamber, which must be periodically emptied in order to allow the continued operation of the