For anyone interested, the following RPO code list was extracted from the 04 J-body factory service manual. I would assume that the 04 codes will apply to other model years, as well.
REGULAR PRODUCTION OPTIONS (RPO) CODE LIST, 2004 J-BODY
AF5 – Easy entry seat adjuster, passenger side
AJ7 - Restraint system seat, inflatable, driver and passenger, front and side
AK5 – Restraint system front seat, inflatable, driver and passenger
AM7 – Seat, right rear, folding
AP9 – Net, convenience
AR9 – Seats, bucket, reclining
AS5 – Seats, deluxe bucket, reclining, w/driver lumbar adjust, seat back pocket, firmer side bolsters
AU0 – Remote keyless entry
AU3 – Power door locks
A31 – Window power operated, side
BW2 – Molding B/S deluxe
BW8 – Ornamentation exterior, emblem, body, rear
B20 – Ornamentation interior, luxury
B25 – Trim, equipment luggage compartment, deluxe
B37 – Covering, floor mats, FRT & RR AUX
CD4 – Wiper system, windshield, pulse
CF5 – Roof, sun, glass, sliding, ELEC
C41 – HVAC, heater system, outside air, w/fan
C49 – Defogger, rear window, electric
C60 – HVAC, air conditioner, front manual controls
C95 – Lamp, interior, roof, courtesy and dual reading
DC4 – Mirror, inside rearview, tilt, dual reading lamps
DG7 – Mirror, outside, remote control, electric, color
DL5 – Decal, roadside service information
DT3 – Box, rear storage compartment
DT4 – Ashtray cigarette lighter
D34 – Mirror, I/S FRT van LH and RH, sunshade, no illumination
D35 – Mirror, outside remote control, color
E02 – Equipment, additional, Caribbean countries
FE1 – Suspension system, soft ride
FE2 – Suspension system, ride handling
FX1 – Ratio, transaxle final drive, 3.94
FX2 - Ratio, transaxle final drive, 3.91
JM4 – Brake system, power, front disc, rear drum, cast iron, antilock, front & rear wheels
J41 – Brake system, power, front disc, rear drum, cast iron
KL6 – Provision, natural gas
K05 – Engine block heater
K34 – Cruise control, automatic, electronic
K62 – Generator, CS 130-D, 105 amp, dual internal fan
LOD – Plant code, Lordstown, OH, BOC
L42 – Engine, flexible fuel, 2.2L, gas CNG, MFI, ALUM, DOHC
L61 – Engine, gas, 4 CYL, 2.2L, MFI, ALUM, DOHC
MM5 – Merchandised TRANS MAN 5 SPD provisions
MN4 – Transmission, automatic 4 speed, 4T40E
MX0 - Merchandised TRANS AUTO provisions, O/D
M86 – Transmission, 5 SPD, OPEL, F23, 5T45MI
NB5 – Exhaust system, single
NC1 – Exhaust system, California, LEV
NF9 – Emission system, general, unleaded
NN5 – Emission override, California system, federal offset vehicle
NP5 – Steering wheel, leather wrapped
NT9 – Emission system, federal, Tier 2 phase-out
NU4 - Emission system, California, LEV2 Plus
NW7 – Traction control; power train MGMT only
N10 – Exhaust system, dual
N33 – Steering column, tilt type
N46 – Steering wheel, deluxe urethane, w/SIR
PA5 – Hubcaps, wheel
PB1 – Wheel cover, 15 inch
PB7 – Wheel, 14 X 6, painted
PC1 - Wheel, 14 X 6, steel
PFC - Wheel, 16 X 6, aluminum, chrome
PFD - Wheel, 16 X 6, aluminum, machined face
PF7 - Wheel, 15 X 6, aluminum, cast, styled
PG0 - Wheel, 16 X 6, aluminum, styled
PG1 - Wheel, 14 X 6, steel
P96 – Equipment, Mexican modification, mandatory, base equipment
QFB – P195/70 R14 all-season, black wall tires
QJN – P205/60 R15-90H, BW, R/ST, TL ALS
QLG – P205/55 R16 performance, black wall tires
QPD – P195/65 R15 touring, black wall tires
RPA – Rear parking assist
SAL – Plant code, Ramos Arizpe, Mexico, GM DE Mexico
SVA – Cup holder
TR2 – Lamp, turn signal, enlarged
TW4 – Package, Cavalier low-priced
T43 – Spoiler, rear
T7N – Parts PKG, miscellaneous parts for police package
T7P – Equipment, MISC EQUIP, Chile
T7V – Fire extinguisher, 2 KG dry chemical
T79 – Fog lamp, rear
T84 – Headlamps, right hand rule of the road, E mark
UA6 – Theft deterrent system
UD4 – Alarm, vehicle speed, 120 K/H
UE1 – Communication system, vehicle, G.P.S. 1
UH8 – Cluster, instrument, cool temp, trip odometer, tach
UL2 – European frequencies
UM6 – Radio, AM/FM Stereo seek/scan, auto reverse, cassette, clock
UM7 – Radio, AM/FM Stereo, seek/scan, clock, ETR
UN0 - Radio, AM/FM Stereo, seek/scan, CD, auto tone, clock, ETR
UQ3 – Speaker system, performance, enhanced audio
US6 – Antenna, fixed, painted, radio
US8 - Radio, AM/FM Stereo, seek/scan, CD, auto tone, clock ETR, MP3, RDS
UW6 – 6 Speaker system, dual F/D tweeter and woofer, dual extended range shelf
UX7 – 4 Speaker system, dual front door mounted, dual extended range package shelf
U05 – Horn, dual
U1C - Radio, AM/FM Stereo, seek/scan, compact disc, clock, ETR
U19 – Speedometer, INST, KILO and miles, KILO odometer
U2E – Cluster, INST, cool temp, trip odometer
U2K – Digital audio system, S-band
U25 – Lamp, interior, rear compartment, courtesy
U79 - Speakers (4), 2 rear shelf, one coaxial each door
U85 – Speaker system (8), quad front door mounted, quad shelf, amplifier
VBX – Language label, Arabic
VB1 – Label, shipping, Japan
VC4 – Label, price/fuel economy, Puerto Rico and Virgin Islands
VC5 – Label, shipping, except US, US possessions or Japan
VC7 – Label, price/fuel economy, Guam
VG8 – Vehicle label, Notice to Buyer
VG9 – Protector, wax, exterior body
VH4 – Front mud guards
VH5 – Plate, vehicle identification
VH9 – Envelope, owner information manual
VK3 – License plate, front, FRT mounting pkg
VK4 – License plate, front, fascia cover
VP6 – Noise control
VR6 – Hook, tie down
VT7 – Owners manual, English language
VY7 – Leather shift knob
V1A – Plant operation, painted exported brake rotors
V1G – Plant operation, Chevy decklid nameplate
V1H – Plant operation, hood blanket
V3C - Plant operation, non-asbestos brake linings
WE4 – Door, dynamic, side impact
Y73 – Parts PKG, deluxe headliner
WL9 – Model conversion, police vehicle
Z49 – Export, Canadian, modification mandatory, base equipment
Z5X – Mirror provisions, Arabic language