Special Vehicles in accordance with definition under Article 13

These vehicles may be sub-divided according to the type of engine used (jet, rocket, etc.).  
 
Article 13 of the International Sporting Code :  
 
Land Vehicle, Automobile, Special Vehicle, Ground Effect Vehicle  
 
Land Vehicle :
Vehicle propelled by its own means in constant contact with the ground either directly by mechanical means or indirectly by ground effect, and the motive power and steering system of which are constantly and entirely controlled by a driver on board the vehicle.  
 
Automobile :
A land vehicle propelled by its own means, running on at least four wheels not aligned, which must always be in contact with the ground; the steering must be ensured by at least two of the wheels, and the propulsion by at least two of the wheels.  
 
Special Vehicles :
Vehicles on at least four wheels which are propelled otherwise than through their wheels.  
 
Ground Effect Vehicle :
Vehicle whose bearing on the ground is maintained by means of a pressurised air cushion.