Also enter the business activity at point A and a brief description of the company`s main product or service at point B. 512100 – Film and video industries (excluding video rental)512200 – Sound recording industries Major business activity codes are based on the North American Industry Classification System. They classify a company according to the type of activity. The list of activities and codes determines from which activity the company derives the largest percentage of its “total turnover”. Also known as IRS business codes. .