what ever it is, is written on page 19 of the options code list
something to do with Nismo
http://www.car-net.jp/car_spec/nissan/skyline/000328.html
One of 500 Special edition Group A GTR Nismo
NISMO Produced Limited Edition 500 Units
Group A ??? (Group A Machine GT-R NISMO)
Model : KBNR32RXFSL-RA
Front Bumper With Air Intake
Small Rear Spoiler
Large Sill?? Protector
Radiator (High-efficiency heat exchanger type)
Large air-cooled Inter Cooler
Metal Turbine
No ABS
NISMO Stickers (Most Important!!)
Electronic Controlled Torque Split 4WD (ATTESA E-TS)
Aluminium(?? Alloy maybe) Opposed Piston Brake
Meter 7500/10000rpm
Fuel injection openings - Right rear
(No, I do not speak/read Japanese )