This Agreement lays down provisions to be applied whenever the presence or the prospective presence of oil or other harmful substances polluting or threatening to pollute the sea within the North Sea area presents a grave and imminent danger to the coast or related interests of one or more contracting parties. For the purposes of this Agreement, the North Sea area shall be that defined by article 2 and it shall be divided into the zones described in the Annex. The Parties undertake to jointly develop and establish guidelines for the practical, operational and technical aspects of joint action. Moreover, they shall exchange the information specified under article 4, regarding for instance their national organization and institutional framework for dealing with pollution. Whenever a contracting party is aware of a casualty or the presence of oil or other harmful substances in the North Sea area likely to constitute a serious threat to the coast or related interests of any other contracting party, it shall inform that party without delay through its competent authority (art. 5).