arrangements established by the Agreement . 2. Each document shall bear a standardized serial The Community and Czechoslovakia shall cooperate closely number , whether or not printed , by which it can be to implement the provisions of the Agreement . To this end , identified . contacts and exchanges of views ( including on technical matters ) shall be facilitated by both parties . This number shall be composed of the following elements : — two letters identifying Czechoslovakia as follows: CS , Article 18 — two letters identifying Member State of destination as In order to ensure the proper application of the Agreement , follows : the.Community and Czechoslovakia shall assist each other in BL = Benelux checking the authenticity and accuracy of export licences and DK = Denmark certificates of origin issued or declaration made under this Protocol . DE = Federal Republic of Germany ES = Spain FR = France Article 19 GB = United Kingdom Czechoslovakiá shall send the Commission of the European GR = Greece Communities the names and addresses of the governmental IE = Ireland authorities competent for the issue and verification of export