 By contrast, in imperial times the cognomen became the principal distinguishing element of the Roman name, and although praenomina never completely vanished, the essential elements of the Roman name from the second century onward were the nomen and cognomen.Naming conventions for women also varied from the classical concept of the "tria nomina".Originally Roman women shared the binomial nomenclature of men; but over time the praenomen became less useful as a distinguishing element, and women's praenomina were gradually discarded, or replaced by informal names.