49 U.S. Code § 33107. Voluntary vehicle identification standards
(a) Election To Inscribe or Affix Identifying Marks.—
The Secretary of Transportation by regulation may prescribe a vehicle theft prevention standard under which a person may elect to inscribe or affix an identifying number or symbol on major parts of a motor vehicle manufactured or owned by the person for purposes of section 511 of title 18 and related provisions. The standard may include provisions for registration of the identification with the Secretary or a person designated by the Secretary.
(b) Standard Requirements.—
The standard under this section shall be practicable and provide relevant objective criteria.
(c) Voluntary Compliance.—
Compliance with the standard under this section is voluntary. Failure to comply does not subject a person to a penalty or enforcement under this chapter.
(d) Compliance With Other Standards.—