++++ Agriculture ° Common organization of the markets ° Milk and milk products ° Butter in public storage ° Sale at reduced prices to processing undertakings ° System of lodging security ° Force majeure ° Concept ° Failure to respect the time-limit for the production of proof of processing in another Member State owing to the inertia of the authorities of the latter ° Case of force majeure ° Condition ° Exercise of all due care by the trader ° Failure to make application for other documents to be accepted as equivalent ° Effect to be assessed in terms of the usefulness of such action (Commission Regulations Nos 1687/76, Art. 14 and 262/79, Art. 22(4))