The pope's title and what he would wear has been a major source of speculation ever since Benedict stunned the world and announced he would resign on Thursday, the first pontiff to do so in 600years.
The Vatican spokesman, the Rev. Federico Lombardi, said Benedict himself had made the decision in consultation with others, settling on "Your Holiness Benedict XVI" and either emeritus pope or emeritus Roman pontiff.
Lombardi said he didn't know why Benedict had decided to drop his other main title: bishop of Rome.
In the two weeks since Benedict's resignation announcement, Vatican officials had suggested that Benedict would likely resume wearing the traditional black garb of a cleric and would use the title "emeritus bishop of Rome" so as to not create confusion with the future pope.
Benedict's decision to call himself emeritus pope and to keep wearing white is sure to fan concern voiced privately by some cardinals about the awkward reality of having two popes, both living within the Vatican walls.
Adding to the concern is that Benedict's trusted secretary, Monsignor Georg Gaenswein, will be serving both pontiffs living with Benedict at the monastery inside the Vatican and keeping his day job as prefect of the new pope's household.
Asked about the potential conflicts, Lombardi was defensive, saying the decisions had been clearly reasoned and were likely chosen for the sake of simplicity.
"I believe it was well thought out," he said.
Benedict himself has made clear he is retiring to a lifetime of prayer and meditation "hidden from the world." However, he still will be very present in the tiny Vatican city-state, where his new home is right next door to the Vatican Radio and has a lovely view of the dome of St. Peter's Basilica.
While he will no longer wear his trademark red shoes, Benedict has taken a liking to a pair of hand-crafted brown loafers made for him by artisans in Leon, Mexico, and given to him during his 2012 visit. He will wear those in retirement, Lombardi said.
Lombardi also elaborated on the College of Cardinals meetings that will take place after the papacy becomes vacant crucial gatherings in which cardinals will discuss the problems facing the church and set a date for the start of the conclave to elect Benedict's successor.
The first meeting isn't now expected until Monday, Lombardi said, since the official convocation to cardinals to come to Rome will only go out on Friday the first day of what's known as the "sede vacante," or the vacancy between papacies.
In all, 115 cardinals under the age of 80 are expected in Rome for the conclave to vote on who should become the next pope; two other eligible cardinals have already said they are not coming, one from Britain and another from Indonesia. Cardinals who are 80 and older can join the College meetings but won't participate in the conclave or vote.
Benedict on Monday gave the cardinals the go-ahead to move up the start date of the conclave tossing out the traditional 15-day waiting period. But the cardinals won't actually set a date for the conclave until they begin meeting officially Monday.
Lombardi also further described Benedict's final 48 hours as pope: On Tuesday, he was packing, arranging for documents to be sent to the various archives at the Vatican and separating out the personal papers he will take with him into retirement.
On Wednesday, Benedict will hold his final public general audience in St. Peter's Square an event that has already seen 50,000 ticket requests. He won't greet visiting prelates or VIPs as he normally does at the end but will greet some visiting political leaders from San Marino, Andorra and his native Bavaria privately afterwards.
On Thursday, the pope meets with his cardinals in the morning and then flies by helicopter at 5 p.m. to Castel Gandolfo, the papal residence south of Rome. He will greet parishioners there from the palazzo's loggia (balcony) his final public act as pope.
And at 8 p.m., the exact time at which his retirement becomes official, the Swiss Guards standing outside the doors of the palazzo at Castel Gandolfo will go inside, their service protecting the head of the Catholic Church now finished.
Benedict's personal security will be assured by Vatican police, Lombardi said.
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