49 C.F.R. § 573.4
For purposes of this part:
Act means 49 U.S.C. Chapter 301.
Administrator means the Administrator of the National Highway Traffic Safety Administration or his delegate.
First purchaser means first purchaser for purposes other than resale.
Leased motor vehicle means any motor vehicle that is leased to a person for a term of at least four months by a lessor who has leased five or more vehicles in the twelve months preceding the date of notification by the vehicle manufacturer of the existence of a safety-related defect or noncompliance with a Federal motor vehicle safety standard in the motor vehicle.
Lessee means a person who is the lessee of a leased motor vehicle as defined in this section.
Lessor means a person or entity that is the owner, as reflected on the vehicle's title, of any five or more leased vehicles (as defined in this section), as of the date of notification by the manufacturer of the existence of a safety-related defect or noncompliance with a Federal motor vehicle safety standard in one or more of the leased motor vehicles.
Original equipment means an item of motor vehicle equipment (other than a tire) that was installed in or on a motor vehicle at the time of its delivery to the first purchaser if the item of equipment was installed on or in the motor vehicle at the time of its delivery to a dealer or distributor for distribution, or was installed by the dealer or distributor with the express authorizations of the motor vehicle manufacturer.
Readable form means a form readable by the unassisted eye or readable by machine. If readable by machine, the submitting party must obtain written confirmation from the Office of Defects Investigation immediately prior to submission that the machine is readily available to NHTSA. For all similar information responses, once a manufacturer has obtained approval for the original response in that form, it will not have to obtain approval for future submissions in the same form. In addition, all coded information must be accompanied by an explanation of the codes used.
Replacement equipment means motor vehicle equipment other than original equipment as defined in this section, and tires.
49 C.F.R. §573.4