w:Allied and Associated Powers, Treaty of Trianon — Part XII. Ports…
“ In the event of Hungary granting a preferential regime to any of the Allied or Associated Powers or to any other foreign Power, this regime shall be extended immediately and unconditionally to all the Allied and Associated Powers.There shall be no impediment to the movement of persons or vessels other than those arising from prescriptions concerning customs, police, sanitation, emigration and immigration, and those relating to the import and export of prohibited goods. Such regulations must be reasonable and uniform and must not impede traffic unnecessarily. ”
