See 2.2.52.1.8 of RID:
"Classification of organic peroxides not listed in 2.2.52.4, 4.1.4.2, packing instruction IBC520 or 4.2.5.2, 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 an RID Contracting State, the classification and conditions of carriage shall be recognized by the competent authority of the first RID Contracting State 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 RID - it has been assigned packing method OP7 according to 4.1.7.1.4 c) of the RID.