From Saint Wiki
Dataria (a papal office). The Dataria, so called from the fact that papal concessions or favors are properly dated, and the date registered by an official of the Pontifical court, is a tribunal from which are issued dispensations pro foro externo, in matters reserved to the Pope. Hence, it is necessary to recur to this tribunal for dispensations from public impediments of marriage and public irregularities. A cardinal is generally at the head of this tribunal; he is named Pro datarius, because the datary is not properly a cardinal's office.