The Federal Motor Vehicle Safety Standards (FMVSS) are U.S. federal vehicle regulations specifying design, construction, performance, and durability requirements for motor vehicles and regulated automobile safety-related components, systems, and design features. They are the U.S. counterpart to the UN Regulations developed by the World Forum for Harmonization of Vehicle Regulations and recognized to varying degree by most countries except the United States. Canada has a system of analogous rules called the Canada Motor Vehicle Safety Standards (CMVSS), which overlap substantially but not completely in content and structure with the FMVSS. The FMVSS/CMVSS requirements differ significantly from the international UN requirements, so private import of foreign vehicles not originally manufactured to North American specifications is difficult or impossible. Structure FMVSS are currently codified in Title 49 of the Code of Federal Regulations, Part 571, Subpart B (), with each FMVSS standard as a section of Part 571, e.g., FMVSS Standard No. 101 is . FMVSS are developed and enforced by the National Highway Traffic Safety Administration (NHTSA) pursuant to statutory authorization in the form of the National Traffic and Motor Vehicle Safety Act of 1966, which is now codified at . FMVSS are divided into three categories: crash avoidance (100-series), crashworthiness (200-series), and post-crash survivability (300-series). The first regulation, FMVSS No. 209, was adopted on 1 March 1967 and remains in force to date though its requirements have been periodically updated and made more stringent. It stipulates the requirements for seat belts in roadgoing vehicles. Other FMVSS include: Crash avoidance FMVSS No. 101: Controls and displays FMVSS No. 102: Transmission shift lever sequence, starter interlock, and transmission braking effect FMVSS No. 103: Windshield defrosting and defogging systems FMVSS No. 104: Windshield wiping and washing systems FMVSS No. 105: Hydraulic and electric brake systems FMVSS No. 106: Brake hoses FMVSS No. 107: [Reserved] (previously "Reflecting surfaces", rescinded in 1996) FMVSS No. 108: Lamps, reflective device and associated equipment FMVSS No. 109: New pneumatic tires for passenger cars FMVSS No. 110: Tire selection and rims for passenger cars FMVSS No. 111: Rear view and side view mirrors FMVSS No. 112: [Reserved] (previously "Headlamp concealment devices", canceled in 1996 and incorporated into #108) FMVSS No. 113: Hood latch system FMVSS No. 114: Theft Protection FMVSS No. 115: [Reserved] (previously "Vehicle identification number", moved to Part 565 in 1983) FMVSS No. 116: Motor vehicle brake fluids FMVSS No. 117: Retreaded pneumatic tires FMVSS No. 118: