(6)For the purposes of efficient use and exchange of reference data, and in order to ensure that reference data are consistent with corresponding data provided in transaction reports, trading venues and systematic internalisers must base the identification of financial instruments and legal entities to be included in the reference data on uniform accepted standards. In particular, and in order to ensure that reference data are matched with corresponding transaction reports, trading venues and systematic internalisers should ensure that International Securities Identifying Number codes in accordance with ISO 6166 pertaining to the financial instruments being reported are obtained and included in the reported data.