The inclusion of the datum DNI in the fields of information that shape the structure of the certificates qualified as public workers would not be, with general character, adapted at the beginning of minimization. From the point of view of the right to the data protection, it is necessary to appraise the possibility to establish a policy of certification that foresees the utilization of certificates based on pseudonyms, to the effects of avoiding the diffusion of this datum, fully valid option in attention to the forecasts of the ReIDAS.