Punched card available, e.g. "80-column card". A sequence of cards that is input to or output from some step in an application's processing is called a "card deck" or simply "deck". The rectangular, round, or oval bits of paper punched out were called chad ("chads") or "chips" (in IBM usage). Sequential card columns allocated for a specific use, such as names, addresses, multi-digit numbers, etc., are known as a "field". The first card of a group of cards, containing fixed or indicative information for that group, is known as a "master card". Cards that are not master cards are "detail cards". The
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