Some states require an industry standard number to be assigned to your company after it is established. The codes do not match business types exactly and you have to make a judgement as the category in which your business should be “tagged”.
The official list is maintained here.
For example, searching for Rental indicates that the code would be 531110 and other Activities related to Real Estate is 5313. Contact your state office if the category is not clearly defined for your specific business activity.