So every new UK car has a unique registration plate that it keeps for it's life.
The only alternative is what's called a private plate, these are 'unique' plates with some sort of unusal aspect (eg spells your initials) and they can be bought and sold independantly of the car.
The plates used to change every year originally the last letter indicated the year, then this became the 1st letter.
This caused a peak in new car sales because everyone wanted the 'new' registration number.
Now we have 2 number changes each year. In March 2006 the 06 plate was released and in Sept 06 the 56 plate was released.
So sherekhans 56 plate means his car was registered on or after the 1st Sept 06 (like mine
)