This is the correct rulebook wording in three places:
3.A.2 Driver’s Helmet:
All drivers/riders shall wear a full-face helmet with face shield. A Snell Foundation tag reading SA2000 or M2000 or later is required. Snell Foundation SA2005 or later certification will be required on all car and motorcycle streamliner helmets beginning on January 1, 2011. No open face helmets will be allowed. Helmets will be visually inspected at least once each year. Helmets shall be undamaged and in serviceable condition. Eyeglasses worn under the helmet shall be shatterproof.
7.C.1 Rider’s Helmet:
All riders shall wear a full-face helmet with face shield, which shall meet Snell Foundation M2000 or later specifications. No open face helmets will be allowed. Helmets will be visually inspected at least once each year. Helmets shall be undamaged, unmodified and in serviceable condition. Eyeglasses worn under the helmet shall be shatterproof. Snell Foundation M2005 or later certification will be required on all helmets beginning January 1, 2011. Snell Foundation SA2005 or later certification will be required on all motorcycle streamliner helmets beginning on January 1, 2011. Riders shall demonstrate proper helmet fit and “roll-off” resistance.
7.H.3 Driver/Rider Suit:
A complete, approved driver/rider suit conforming to SFI specification 3.2A/15 is REQUIRED. Gloves and boots shall be SFI specification 3.3/5 rating. A SFI specification 3.3 head sock shall be worn under the helmet. Snell Foundation SA2005 or later certification will be required on all motorcycle streamliner helmets beginning on January 1, 2011.