PROC FORMAT creates user-defined formats to categorize the number of cake layers and the cake flavors. NOTSORTED keeps $FLVRFMT unsorted to preserve the original order of the format values. 
proc format;
   value layerfmt 1='single layer'
                  2-3='multi-layer'
                  .='unknown';
   value $flvrfmt (notsorted)
                  'Vanilla'='Vanilla'
                  'Orange','Lemon'='Citrus'
                  'Spice'='Spice'
                  'Rum','Mint','Almond'='Other Flavor';
run;