I was entrusted with the coordination of the project funded by the Biblioteca nazionale centrale of Florence for the Feasibility study about the renewal of the Soggettario per i cataloghi delle biblioteche italiane, the indexing tool used also by the Bibliografia nazionale italiana (BNI). The initiative by the National Library was managed respecting international standards, IFLA recommendations and confiding in the contribution of indexing traditions and experiences that are different from ours. The work ended in may of the last year. In this paper I’ll describe its features and potentialities in relation to the implications that its future use is likely to have in the field of authority control.