Sweden is a constitutional monarchy, and King Carl XVI Gustaf is the head of state, but the role of the monarch is limited to ceremonial and representative functions. Under the provisions of the 1974 Instrument of Government, the King lacks any formal political power. The King opens the annual Riksdag session, chairs the Special Council held during a change of Government, holds regular Information Councils with the Prime Minister and the Government, chairs the meetings of the ''Advisory Council on Foreign Affairs'' (), and receives Letters of Credence of foreign ambassadors to Sweden and signs those of Swedish ambassadors sent abroad. In addition, the King pays State Visits abroad and receives those incoming as host. Apart from strictly official duties, the King and the other members of Royal Family undertake a variety of unofficial and other representative duties within Sweden and abroad.