Can someone help here?

The following is from the Chesapeake Bay PHRF application
4. SAILS: [ ] Request BOTH Spinnaker and NS ratings -- (Provide all mainsail, headsail, and spinnaker info required below)
[ ] Request ONLY a NS rating -- Will not race with spinnakers this season (Provide the mainsail and headsail info required below)
MAINSAIL: Number Battens: _____; Using Roller Furling Mainsail; furling in the [ ] Mast, or furling in the[ ] Boom;
Oversize girth mainsail? [ ] No, [ ] Yes; If Yes, record following dimensions. Headboard _____, MGT_____, MGU_____, MGM_____, MGL_____
HEADSAIL: Largest jib/genoa: Midgirth less than or equal 50%. Overlap (LP): _______.____ft., and/or (Overlap percentage): %LP__________
[ ] Using Roller Furling Headsails: RF Sailcloth is: [ ] Woven(Dacron/other), or [ ] Lam/molded (Mylar, Kevlar, Spectra, etc.)
RF Laminated sail cloth protected on both sides by taffeta skin? [ ]Yes, [ ] No; Year/month RF Headsail was built ( ________/_______)
RF Headsail has leech and foot cover of UV protected woven material of at least 4.0 oz? [ ] Yes, or [ ] No
RF Headsail drum is installed above deck level [ ]; or RF Headsail drum is installed at, or below deck level [ ].
[ ] Using "Code 0", or Sail with Midgirth between 50% and 75% (record measurements below)

I couldn't find anything in the application nor in the document labeled PHRF rating system that addresses sail material. The only mention to sailclothe material is in the section about Roller Furling sails - and there it says Laminated Mylar, Kevlar sails are leagal.

Perhaps I've missed something, the only conclusion I can draw is that the J/30 is penalized for non-conformance to OD configuration. If that's true, then if the J/30 Class allows string sails, the Chesapeake sailors would no longer be penalized