1. The provisions of this Protocol concerning the methods of exercise of juxtaposed frontier controls, particularly any extension or reduction of their field of application, may be modified by mutual agreement between the Governments by way of arrangements which shall be confirmed by Exchange of Diplomatic Notes.
2. In an emergency, the local representatives of the authorities concerned may by mutual agreement provisionally bring into effect alterations to the delimitation of the Control Zones which may prove necessary. Any arrangements so reached shall come into effect immediately.