Source : Free On-Line Dictionary of Computing

for values of
     
         A common rhetorical maneuver at {MIT} is to use any
        of the canonical {random numbers} as placeholders for
        variables.  "The max function takes 42 arguments, for
        arbitrary values of 42".  "There are 69 ways to leave your
        lover, for 69 = 50".  This is especially likely when the
        speaker has uttered a random number and realises that it was
        not recognised as such, but even "non-random" numbers are
        occasionally used in this fashion.  A related joke is that pi
        equals 3 - for small values of pi and large values of 3.
     
        This usage probably derives from the programming language MAD
        ({Michigan Algorithm Decoder}), an {ALGOL}-like language that
        was the most common choice among mainstream (non-hacker) users
        at {MIT} in the mid-1960s.  It had a {control structure} FOR
        VALUES OF X = 3, 7, 99 DO ... that would repeat the indicated
        instructions for each value in the list (unlike the usual FOR
        that generates an {arithmetic sequence} of values).  MAD is
        long extinct, but similar for-constructs still flourish
        (e.g. in {Unix}'s {shell} languages).
     
        [{Jargon File}]
     
        (1994-12-16)