17. Producers who are online marketplace operators must—
(a)where the producers are small producers, keep records of the information set out in paragraphs 18 and 19, and provide a description of the methodology they use to collate that information to NRW;
(b)where the producers are large producers, keep records of, and report on, the information set out in paragraphs 18 and 19, and provide a description of the methodology they use to collate that information to NRW.