[ESMA 70-872942901-35 MiFIR transparency Q&A, Q&A 2.5]

Pre-trade transparency information should allow identifying unequivocally the financial instrument to which the information published refers. ISINs are one of the available ways to ensure the unequivocal identification of a financial instrument. However, ESMA recognises that ISINs may not always be available when providing a quote. Trading venues and systematic internalisers are free to use other ways for identifying instruments for pre-trade transparency purposes as long as the financial instrument can be unequivocally identified.