The paper discusses the reasons of users' dissatisfaction in the use of present online catalogues, that arise from the failure of catalogues in offering a systematic view of presentation of the bibliographic universe and even less in organizing knowledge effectively. The paper presents the concept of granularity and compares it with the three scenarios for the implementation of RDA - Resource Description and Access that Tom Delsey defined in 2006. The paper shows how these scenarios can be implemented in the only two cataloguing codes written after FRBR (REICAT. Regole italiane di catalogazione and RDA) and it highlights how logical improvements derived from FRBR turn into specific devices, that require to change data structure of the catalogue and, consequently, of cataloguing software.