Federal regulations implement the laws written by Congress (the U.S. Code), and set forth policies for federal departments. It's important to follow regulations, as they have the full force and effect of laws.
The Federal Acquisition Regulation System is Title 48 of the Code of Federal Regulations. It regulates the federal government's acquisition process for goods and services. Federal departments publish supplements to the FARS in numbered chapters.
Defense Supply Centers are the main Inventory Control Points of the Defense Logistics Agency. Each center can issue its own regulations, which add to the FARS and other regulations.
The International Traffic in Arms Regulations is part of Title 22 of the Code of Federal Regulations. It implements the Arms Export Control Act, controlling the goods pertaining to defense and the military, as well as certain types of technology and information.