such separation may be replaced by an appropriate accounting system which ensures that no more goods are deemed to originate in the Member States than would have been the case if the producer had been able physically to separate the materials. 2. Any such accounting system shall conform to such conditions as may be agreed upon by the CMT in order to ensure that adequate control measures shall be applied. RULE 8 TREATMENT OF MIXTURES 1. In the case of mixtures, not being groups, sets or assemblies of goods dealt with under Rule 6 of this Annex, any product resulting from the mixing together of goods would qualify as originating in the Member States with goods which would not qualify , if the characteristics of the product as a whole are not different from the characteristics of the goods which have been mixed. 2. In the case of particular products where it is recognised by the CMT to be desirable to permit mixing of the kind described in paragraph 1 of this Rule, such products shall be accepted as originating in the Member States in respect of such part thereof as may be shown to correspond to the quantity of goods originating in the Member States used in the mixing, subject to such conditions as may be agreed by the CMT. RULE 9 TREATMENT OF PACKING 1. Where for purposes of assessing Customs duties a Member State treats goods separately the origin of such packing, it may also, in respect of its imports consigned from another Member