data processing techniques. 4. Whenever practicable, computer applications implemented by Customs authorities of Member States should use internationally accepted standards, especially those adopted by the World Customs Organisation, the United Nations Economic Commission for Africa and UNCTAD. 5. The Customs authorities of Member States shall consider developing or adopting common customs applications systems. They shall consult with other agencies, national and international, when considering the development or adoption of new systems or the enhancement of existing ones with a view to avoiding duplication of effort where possible. 6. In automating procedures, Customs authorities of Member States shall allow the possibility of interchanging data with trade users by direct link on machine - readable media according the technology available. ARTICLE 7 PRESERVATION, INVESTIGATION AND SUPPRESSION OF CUSTOMS OFFENCES 1. Member States undertake to co-operate in the prevention investigation and suppression of Customs offences. 2. For the purposes of paragraph 1 of this Article, the Member States undertake to: a) exchange lists of goods and publications, the importation of which is prohibited in their respective territories; b) prohibit the exportation of goods and publications referred to in sub-paragraph (a) of