The # column is the rank of each listed entry for Riccardo Vari — rank 1 means this entry is where Riccardo Vari has the most articles or citations. A pos and C pos show the reciprocal: the position of Riccardo Vari within that entry's own ranked list, by articles and citations respectively. A low value means Riccardo Vari is among the most prominent contributors for that entry.
