Article 9
1. Member States shall adopt the additional measures necessary: - to ensure that the co-responsibility levy is collected in accordance with this Regulation, and in particular control measures. Such controls may be conducted by spot checks; - to ensure the application of the exception for seed grain provided for in Article 1 (1); to that end Member States may make provision for the application nationally, per cereal, of a coefficient expressing the ratio between the quantity of seed certified and sold and the quantity of seed purchased under a multiplication contract. They may also fix a minimum level of certification below which a seed merchant may no longer apply the standard coefficient referred to above. Where such a coefficient is applied, the Member State in question shall, at the end of the marketing year, update the coefficient to be applied in the following marketing year. They may also require operators to provide any information in addition to that mentioned in the Annex. 2. Member States shall notify the Commission of the measures referred to in paragraph 1 before 1 August 1988. The Commission undertakes to confer beforehand with Member States which so request.