Immovable property taxation: income is taxable in the state where the property is situated, covering usufruct and extraction rights. Income from immovable property may be taxed in the Contracting State where the property is situated; immovable property is defined by that State's law and includes accessories, agricultural livestock and equipment, rights governed by landed property law, usufruct, and rights to payments for working mineral deposits and other extraction sites, while excluding ships and aircraft. The situs taxation rule applies to income from direct use, letting or other uses of immovable property and extends to property income of enterprises and property used for professional services.