AB = Articulated Bus
B = Rigid bus
C = Coach
H = High bridge double decker
L = Low bridge double decker
then
nn = Number of seats minus driver
then
D = Front and centre doors
F = Front door only
FR = Front and rear doors
T = Tri-door (i.e. front, centre, rear)
then
w = Wheelchair accessible (note lower case)
For example: AB60Tw is an accessible articulated bus with 60
seats and three doors.