++++ 1. Agriculture ° Common organization of the markets ° Milk and milk products ° Butter from public storage ° Sale at a reduced price to processors ° Obligation to ensure a uniform diffusion of the tracer products which have to be incorporated in the course of processing of concentrated butter ° Burden of proving non-compliance rests on the competent national authorities ° Discretionary power regarding details of supervision ° Examination of their probative value under national law (Commission Regulation No 262/79 Art. 5(2) and Art. 22(5)) 2. Agriculture ° Common organization of the markets ° Milk and milk products ° Butter from public storage ° Sale at a reduced price to processors ° Rules on security ° Obligation to incorporate tracer products in the butter to prevent it from being diverted from its intended use ° Non-compliance ° Forfeiture of the security for the batch concerned ° Principle of proportionality ° Breach ° Absence (Commission Regulation No 262/79 Art. 22(5))