Capital gains taxation: source State may tax immovable and PE related disposals; other gains taxable in resident State. Gains from alienation are taxed based on property type and nexus: immovable property is taxable in the State where situated; gains tied to movable property of a permanent establishment or fixed base may be taxed in the State of that establishment or base; disposals of ships or aircraft in international traffic are taxable only in the State of the enterprise's residence; disposals of shares in property rich companies may be taxed in the State where the immovable property is located; remaining gains are taxable only in the alienator's State of residence.