31.12. 91 Official Journal of the European Communities No L 374/1 (Acts whose publication is obligatory) COUNCIL REGULATION (EEC) No 3924/91 of 19 December 1991 on the establishment of a Community survey of industrial production THE COUNCIL OF THE EUROPEAN COMMUNITIES, Having regard to the Treaty establishing the European Economic Community, and in particular Article 213 thereof, Having regard to the draft Regulation submitted by the Commission, Whereas in order to carry out the tasks devolving on it from the Treaties, especially with the prospect of the internal market as provided for pursuant to Article 8a of the Treaty establishing the European Economic Community, the Commission must have full, up-to-date and reliable information on industrial production in the Community; Whereas companies need such information in order to know their markets; whereas the international dimension of these markets will favour an alignment between production statistics and external trade statistics; Whereas, if production statistics are to be useful and in order to make such an alignment practicable, they must be drawn up at a level of detail which is close to the first six digits of the combined nomenclature, which also corresponds to the coding used in the Harmonized System; Whereas the combined nomenclature is a product nomenclature with which companies are already familiar; whereas it is in their interests to refer thereto rather than create a nomenclature specific to production; Whereas standardized statistics cannot be drawn up with the reliability, speed, flexibility and level of detail required to manage the internal market unless the Member States use survey classification systems derived from the same product list; ’ Whereas, in order to meet national requirements, Member States may legitimately retain or enter in their national nomenclatures supplementary items not contained in the Community product list, HAS ADOPTED THIS REGULATION: Article 1 General Member States shall carry out a Community statistical survey of industrial production. Article 2 Survey field and characteristics 1.  The field covered by the survey referred to in Article 1 shall be that of the activities listed in sections C, D and E of the classification of economic activities in the European Community hereafter referred to as ‘NACE (Rev. 1)’ set out .in Regulation (EEC) No 3037/90 (). 2.  The production recorded in this field shall be defined by the list of products, hereinafter referred to as the ‘Prodcom list’, the headings of which shall in principle consist of articles or groups of articles from the combined nomenclature linked with other Community product nomenclatures. 3.  The survey shall cover the following information for each heading: (a) the physical volume of production sold during the survey period; i (b) the value of production sold during the survey period. ’ 4. In certain cases the information in question- shall be replaced by one of the following: (a) the physical volume of actual production during the survey period, including any which is incorporated into the manufacture of other products from the same undertaking; (b) the value and/or physical volume of actual production during the survey period with a view to marketing. (1) OJ No L 293, 24. 10. 1990, p. 1.