Source : Free On-Line Dictionary of Computing

computer confetti
     
         (Or "{chad}") A common term for {punched-card}
        {chad}, which, however, does not make good confetti, as the
        pieces are stiff and have sharp corners that could injure the
        eyes.
     
        {GLS} reports that he once attended a wedding at {MIT} during
        which he and a few other guests enthusiastically threw chad
        instead of rice.  The groom later grumbled that he and his
        bride had spent most of the evening trying to get the stuff
        out of their hair.
     
        [{Jargon File}]
     
        (2001-06-22)