PHONENUM.CTL : Use this file to  specify phone  numbers or
                  segments  of phone  numbers that you know
                  to be false. A PHONENUM.CTL that contains:

                        00-
                        000-
                        -0000


                  Would  disallow  the numbers  "00-123-4567",
                  "000-123-4567",  "009-0000-1234".  The  rule
                  here  is that none of the specified  numbers
                  is  allowed to be imbedded anywhere  in  the
                  user's phone number.