The above is a picture of the RPO sheet for my Trans Am.  RPO stands for Regular Production Order.  This is the definition of what options were installed on the car to make sure the dealership would put the appropriate parts on the car when it was in for servicing.

Here is a definition of what those codes mean for my car:

Thanks to ThirdGen.org's RPO Decoder!

AAA : 4-WAY MANUAL SEAT ADJUSTER 
AH3 : ADJUSTER, 4-WAY MANUAL, DRIVER SEAT 
AJ3 : RESTRAINT SYSTEM, FRT SEAT, INFLATABLE, DRIVER 
AR9 : SEAT, FRT BKT, EUROPEAN STYLE, PASS A DRIVER RECL 
AU3 : LOCK CONTROL, SIDE DR, ELEC 
A31 : WINDOW, POWER OPERATED, SIDE 
A90 : LOCK CONTROL, RR COMPT LID, REM CONT ELEC RELEASE 
BC8 : ORNAMENTATION, INTR, DR MAP POCKETS 
B84 : ORNAMENTATION, EXTR MLDG, B0DY SIDE 
CC1 : ROOF HATCH, REMOVABLE PANELS, GLASS 
C49 : DEFOGGER, RR WINDOW, ELECTRIC 
C60 : HVAC SYSTEM, AIR CONDITIONER FRT MAN CONTROLS 
DC4 : MIRROR I/S, R/V, TILT, DUAL READING LAMPS 
DE4 : SUNSHADE, REMOVEABLE HATCH ROOF 
DG7 : MIRROR 0/S, LH & RH, REM CONT, ELEC, PAINTED 
D7C : GEAR, SPEEDO DRIVEN 
D8N : SENSOR, VEH SPD 
D81 : SPOILER, RR, AERO WING 
E5Z : SPEEDOMETER ADAPTER (DELETE) 
E9Z : SPEEDOMETER KEY (DELETE) 
FE2 : SUSPENSION SYSTEM, RIDE HANDLING 
GU2 : AXLE REAR, 2.73 RATIO 
G80 : AXLE POSITRACTION, LIMITED SLIP 
IPC : TRIM- INTERIOR DESIGN
JG1 : SHAFT, PROP, ALUMINUM 
J42 : BRAKE SYSTEM, PWR. FRT DISC, RR DRUM, ALUMINUM 
K34 : CRUISE CONTROL, AUT0MATIC, ELECTRONIC 
K68 : GENERATOR,105 AMP 
LB9 : ENGINE, GAS, 8 CYL, 5.0L, TPI, HO 
MD8 : TRANSMISSION, AUTO 4 SPD, THM 700 R4 
MXO : MERCHANDISED, TRANS, AUTO PROVISIONS, O/D 
NA5 : EMISSION SYSTEM, FEDERAL, TIER O 
NP5 : STEERING WHEEL, LEATHER WRAPPED 
N64 : WHEEL & TIRE, SPARE, SPACE SAVER, ALUMINUM 
PW7 : WHEEL, 16 X 8, ALUMINUM, DIAMOND SPOKE 
QLC : TIRE ALL, P245/50ZR16/N BL R/PE ST TL HW4 
R9Z : Unable to locate code
T93 : LAMP, TAIL & STOP, SPECIAL 
T96 : LAMP, FOG 
UB3 : CLUSTER, INST, OIL, COOL TEMP, VOLTS, TRIP ODOM, TACH 
UQ1 : RADIO PROVISIONS, FOR STEREO 
UX1 : RADIO, AM/FM STEREO CASSETTE EQUALIZER 
U62 : SPEAKER SYSTEM, DUAL COAXIAL 
VAN : ASSEMBLY PLANT, VAN NUYS, CA 
V73 : ANTENNA, FIXED 
WS4 : MODEL CONVERSION, TRANS AM 
WS6 : PERFORMANCE PACKAGE, SPECIAL 
Y83 : MERCHANDISED PKG, TRANS AM 
1SC : PACKAGE, OPTION 03 (Power Windows, Power Door Locks, Remote Hatch Pop, Body Side Moldings, Rear View Mirror with Map (Flood) Lights, Power Mirrors and Cruise Control)
1SZ : PACKAGE, SALES 
18P : WHEEL COLOR, CHARCOAL MET (91) 
6ZX : SPRING, COMPUTER SELECTED, FRONT, LEFT HAND 
7ZX : SPRING, COMPUTER SELECTED, FRONT, RIGHT HAND 
8NL : COMPUTER SELECTED REAR LEFT HAND SPRING
81Q : MOLDING COLOR, BRIGHT RED (91) 
81U : PRIMARY COLOR, EXTERIOR, BRIGHT RED (91) 
82C : TRIM COMBINATION, CLOTH, MED DK GRAY (C) (91) 
82I : INTERIOR TRIM, MED DK GRAY (91) 
829 : SEAT BELT COLOR, MED DK GRAY (91) 
9NL : SPRING, COMPUTER SELECTED, REAR, RIGHT HAND