It simplifies the documentation, designates the type approval number of a separate technical unit by a certificate of conformity, and defines the vehicles, individual technical units, and components. Certificates of conformity, as specified in Annex IX of EU Directive 92/53, will be required for an automobile to enter into service. For component approvals, an endorsement that is issued under the relevant regulations by the U.N. Economic Commission for Europe (UNECE) is recognised as equivalent to an approval granted under comparable EU legislation. In March 1992, the EU Council formally adopted the few remaining pieces of component-related legislation that are necessary to make the whole-vehicle type approval a reality for passenger cars. In June 1992, EU member state officials approved the adoption of EU legislation creating a single system for the certification of passenger cars, in turn defining the safety, and other technical, requirements. Legislation established an EU type approval system to replace the national schemes of the twelve member states. In 1996, the EU type approval system became mandatory.