Seriously? So my 3.5 layer Nomex III, PBI, Nomex batt, 3.5 oz. Nomex tricot suit isn't safe enough now?[/b]
Best I can tell, yes. New rule reads as follows (effective 11/1/07, which means if someone used something else at the ARRC they were illegal...any typos are my own...)

Effective 11/1/07: Change section 9.3.19.A as follows:
Driving suits that effectively cover the body from the neck to the ankles and wrists. One piece suits are highly recommended. All suits shall bear an SFI 3.2A/1 or higher certification label or FIA 8856-2000 homologation. Underwear of fire resistant material shall be used except with suits carrying FIA standard 8856-2000 or
SFI 3-2A/5 or higher (e.g., /10, /15, /20) Certification Patch.