Residence-based taxation of employment income with limited source-state taxation where short-term presence and employer conditions apply. Article 15 establishes that employment remuneration is taxable only in the employee's State of residence unless the employment is exercised in the other State, in which case that State may tax the remuneration. An exception prevents source-state taxation where three conditions coexist: presence not exceeding 183 days, payment by an employer not resident in the source State, and the remuneration not borne by a permanent establishment. Remuneration of seafarers and aircrew in international traffic is taxable only in the State of residence.