P R N D 2 L is most likely your transmission.
P=Park, locks the transmission with a parking pawl/pin and the front 2 wheels are locked. If the handbrake is down and gear in Park, your car wont go anywhere regardless of the in/decline.
N=Neutral, all 4 wheels free and used primarily for towing purposes.
D=All gears active, in a Vitz it means 4 gears.
2=Transmission is restricted only to 2 gears and the gearbox will not allow the car to exceed 2nd gear. Used for towing and climbing/going down inclines. Max speed around 30-45km/h
L=Transmission is restricted only to 1 gear and the gearbox will not allow the car to exceed 1st gear. Used when maximum engine power is needed. Max speed around 20-30km/h
od is overdrive and gives an extra gear for efficiency & speed I believe.