See 2.2.52.1.8 of ADN:

"Classification of organic peroxides not listed in 2.2.52.4, 4.1.4.2 of ADR, packing instruction IBC520 or 4.2.5.2 of ADR, portable tank instruction T23, and assignment to a collective entry shall be made by the competent authority of the country of origin. The statement of approval shall contain the classification and the relevant conditions of carriage. If the country of origin is not a Contracting Party to ADN, the classification and conditions of carriage shall be recognized by the competent authority of the first country Contracting Party to ADN reached by the consignment."

This BAM No. represents the generic entry itself, provided that the organic peroxide also has corrosive properties within the meaning of ADN - it has been assigned packing method OP6 according to 4.1.7.1.4 b) of the ADR. A packing method with a lower OP number may be indicated in the approval certificate of the competent authority if the organic peroxide meets the criteria of the Manual of Tests and Criteria, para. 20.4.3 b) only in a smaller packaging.