Cruising Code Zeros are designed with straight luff incorporating an anti-torsion rope and a small positive roach for stable trim and easy handling.  They can be built out of heavy spinnaker cloth, which is most competitive, or a laminate for more demanding cruising sailors.  Race Code Zeros are built out of Dimension Polyant CZ Laminate.  The mid girth of Racing Code Zeros is designed to be 75% of foot to avoid rating penalties which does mean a small downturn in wind range and handling but this is accepted by racers because of the advantages in rating.