Apostolic constitution by Paul VI
Romano Pontifici eligendo was the apostolic constitution governing the election of popes that was promulgated by Pope Paul VI on 1 October 1975. It instituted a number of far-reaching reforms in the process of electing popes. It set the maximum number of electors at 120 and restated in a more formal context the rule he had already instituted that cardinals over the age of 80 not participate in electing a pope.
The constitution was superseded by Universi Dominici gregis.