/* Create a sample format */
proc format;
   value id   1='Mary'
              2='Tom'
              3='Joe';
run;

/* The CNTLOUT= option creates an output data set from an existing format */
proc format cntlout=outfmt;
   select id;
run;

/* Create a new data set that includes the values */
/* from OUTFMT as well as a new format label.     */ 
data newfmt;
   length label $ 20;
   retain start;
   set outfmt end=last;
   output;
   if last then do;
      start=4;
      end=4;
      label='New Employee';
      output;
   end;
run;

/* The format is re-created using the CNTLIN= option to point to the  */
/* new data set containing the updated information for the old format */
proc format cntlin=newfmt fmtlib;
run;