§ 263.4 Registration of vehicles.
Primary source
Verbatim text below is from the Electronic Code of Federal Regulations (eCFR), a public-domain U.S. government work. Always verify the current version with the eCFR before relying on it for any legal matter.
Full Text
(a) Newly assigned or employed individuals who intend to operate a privately-owned vehicle at the site shall register it with the Security Police Division within 24 hours after entry on duty.
(b) Temporary registration for a specified period of time will be permitted for temporarily hired, detailed, or assigned personnel; consultants; contractors; visiting dignitaries, etc.
This is legal information, not legal advice. Laws vary by jurisdiction and change frequently. Always verify current law with official sources and consult a licensed attorney in your jurisdiction for advice on your specific situation.