The notation "V" is not a tribute to the name of von Neumann. It was used for the universe of sets in 1889 by Peano, the letter "V" signifying "Verum", which he used both as a logical symbol and to denote the class of all individuals. Peano's notation "V" was adopted also by Whitehead and Russell for the class of all sets in 1910. The "V" notation (for the class of all sets) was not used by von Neumann in his 1920s papers about ordinal numbers and transfinite induction. Paul Cohen explicitly attributes his use of the letter "V" (for the class of all sets) to a 1940 paper by Gödel, although Gödel most likely obtained the notation from earlier sources such as Whitehead and Russell.