TSD CLASSES

Class A (Unlimited): Any type of rally equipment is allowed.

Class B (Equipped): Any type of navigational device, calculator, or computer
is allowed, including auxiliary odometers and laptop computers, except for
devices which calculate perfect time from inputs generated by the vehicle's
motion.

Class C (Unequipped): Restricted to original-equipment instruments and
onboard computers, handheld four-function calculators, and any timepiece.