According to their annual financial contributions to the IIR, these member countries are divided into six category levels and this determines the services they receive and their level of voting power within the IIR. Member Countries take part in IIR activities via their delegates and their nominated commission members. The delegates and commission members determine IIR priorities and take part in the IIR scientific activities and Working Groups, and develop recommendations. Member countries are entitled to host several IIR conferences and meetings per year.