[mts]

Yep, you learn something new every day, J-RAD, you are certainly correct and I am mistaken. From the Nord Stern region:

"All car occupants must wear a Snell approved helmet , which has the current available Snell rating or the one previous Snell rating."

In contrast, a few regions I run with:

Peachstate - "All Helmets must be Snell rated SA2000 or better".
Ohio Valley - "All helmets must meet minimum SA2000 requirements."
Kentucky Region - "All helmets must be SA2000 or SA2005 approved."
Central Indiana Region - "Helmets - Snell Special Application rating (SA2000 or SA2005) required. Snell motorcycle helmets (M95, M00, M05) or non-Snell rated helmets will NOT be permitted. "

I'm suprised it varies like that, but it does.