9. This Part has effect with respect to the approval by the Secretary of State under section 42(1) of the Act of a particular regulated public service vehicle as satisfying the provisions of these Regulations, and in this Part and in Part V and Schedules 5 and 6 a vehicle which has been so approved is referred to as a “type vehicle” and an approval so given (which may be in such form as the Secretary of State may determine) is referred to as a “type vehicle approval”.