49 CFR 571.500

What this standard covers, in our words

The mandatory United States federal motor vehicle safety standard for LOW-SPEED VEHICLES — a four-wheeled motor vehicle, other than a truck, whose attainable speed over one mile is more than 20 mph but not more than 25 mph. It requires headlamps, front and rear turn signal lamps, taillamps, stop lamps, reflex reflectors, mirrors, a parking brake, a conforming windshield, seat belts and a VIN. It is a legal requirement rather than a voluntary certification, it governs the VEHICLE and not the battery, and a cart that is not an LSV is not subject to it.

This is our summary, not the standard’s own wording — National Highway Traffic Safety Administration (NHTSA) publish the text itself and it is the document to read before relying on anything here.