i can understand your feelings for getting delayed answer.
Still I rate this this thread very high & informative.
coming to your question, please find answer below.
P = Parking
R = Reverse
N = Neutral
D = Drive
S = (Super Drive, with more power,acceleration,torque & less gear change, normally it use while overtaking & speeding.
B = (Braking, it normally uses in hilly & mountain range. car use less gear but great acceleration yet provide super & ultimate braking required in hilly areas.
I hope answer the question.