Article 4(1) and the first subparagraph of Article 4(4) of Sixth Council Directive 77/388/EEC, on the one hand, and the first subparagraph of Article 9(1) and Article 10 of Council Directive 2006/112/EC of 28 November 2006 on the common system of value added tax, on the other, must be interpreted as meaning that multiple civil-law partnerships, such as those at issue in the main proceedings, which conduct themselves outwardly as such and independently in relation to their suppliers, public authorities and, to a certain extent, their customers, and each of which carries out its own production by using for the most part its means of production, but which market a large proportion of their products under a common trade mark through a limited company the shares in which are held by members of those civil-law partnerships and by other members of the family in question, must be regarded as independent undertakings which are taxable persons for value-added-tax purposes. Article 25 of Sixth Directive 77/388 and Article 296 of Directive 2006/112 must be interpreted as not excluding the possibility of refusing the application of the common flat-rate scheme for farmers, laid down in those articles, to multiple civil-law partnerships, such as those at issue in the main proceedings, regarded as independent undertakings which are taxable persons for value-added-tax purposes and which cooperate with each other, on the ground that a limited company, an association of persons made up of that limited company and members of the civil-law partnerships in question could not be subject to that scheme, on account of the size of its operation or its legal form, even if those civil-law partnerships do not belong to a category of producers excluded from that flat-rate scheme, in so far as they are, owing to their links with that company or one of those associations, materially capable of assuming the administrative burden of the tasks arising from the application of the normal arrangements or the simplified scheme, this being a matter for the referring court to verify. In the event that the common flat-rate regime for farmers has, in principle, to be excluded for civil-law partnerships such as those at issue in the main proceedings, such an exclusion would apply to the period prior to the date on which the appraisal on which it is based took place, provided that that appraisal occurs within the limitation period for action on the part of the tax authority and its effects do not apply retroactively to a date earlier than that on which the legal and factual elements on which it is based occurred.