If you want to start a new company, you have to register the type of business that you will be pursuing in your day to day activities. For example, if you want to establish a mining operation or an engineering firm or a hair saloon in Virginia, the State Corporation Commission requires specific code numbers you must fill in the incorporation documents. These code numbers are issued by the North American Industry Classification System association, hence the name "NAICS codes" (https://www.naics.com). The same classification numbers in Hungary are called "Statisztikai számjel", maintained by the Központi Statisztikai Hivatal. These codes include the so called "TEÁOR" numbers, (Gazdasági Tevékenységek Egységes Ágazati Osztályozási Rendszere), which directly correspond to the American system.