DIVIDING VARIABLES INTO CODES OR RANGES

  Perhaps you have variables (or columns) which classify other variables
into groups.  If you designated such a grouping variable earlier, then BMD
will automatically take the 10 lowest values of that variable as codes.
But, you may state explicitly what the codes are, or state explicity
what the value ranges are that serve as coding ranges.

  Any variables may be broken down into codes or ranges of values;
they need not be grouping variables. The program will ask for them
one at a time. Respond by entering the number of the variable reflecting
the order in which the variable was named when variables were entered.

  The default option enters the first variable in the variable list
as the variable for which grouping is desired.