Vatican City, February 21 - The pope could issue a special statement on the rules of the upcoming conclave to elect his successor, without permanently changing the substance of the rules, a Vatican spokesman said Thursday. Pope Benedict XVI, who is retiring as of February 28, could issue a 'motu proprio' on the conclave involving "possible adjustments" to its timing, Vatican Spokesman Father Federico Lombardi confirmed A motu proprio is a document that popes can use to make changes to Church law or procedure. But the world will have to "wait to see" what the pope ultimately chooses to do, he added. Such changes could allow the conclave to occur earlier than mid-March. The Vatican initially said that the conclave would not take place until 15 to 20 days after Benedict leaves the position on February 28, in accordance with Church rules. But some say the conclave may start earlier, given that the pope has not died, but has quit and therefore given cardinals plenty of notice of the election to come. Many cardinals are already in Rome and they have begun informal talks about what sort of person the next pope should be.