Vatican City, Mar 11, 2013 / 12:25 pm

This evening 90 people who will assist the Conclave in various capacities took an oath of secrecy not to divulge anything about it or the events surrounding it.

Among the people participating are "religious for the sacristy, religious for confession, nurses and doctors, waiters and food service personnel from Santa Marta, technical assistants, and people who clean Santa Marta and the Vatican," said Vatican press director Father Federico Lombardi at a March 11 briefing.

The list also includes less obvious personnel, such as florists, minibus drivers who transport the cardinals to the Sistine Chapel, and the heads of the Swiss Guard and Vatican Police.

The ceremony was presided over by Cardinal Tarcisio Bertone in the Pauline Chapel at 5:30 p.m.

All of the cardinals – both electors and non-electors – will gather together one last time on Tuesday morning in St. Peter's Basilica for the Mass to Elect a Roman Pontiff.

The Mass will not be ticketed and will be open to the faithful.

At 4:30 in the afternoon, the cardinals will be admitted to the Conclave by Cardinal Giovanni Battista Re in the Pope's private chapel, known as the Pauline Chapel.

He will say: "Venerable Brothers, after having celebrated the divine mystery, we now enter into Conclave to elect the Roman Pontiff."

The cardinals will then process to the Sistine Chapel, with Archbishop Georg Gänswein in the lead as head of the Pontifical Household, and they will sing the litany of the saints.

When they arrive in the chapel they will sing "Veni Creator Spiritus" and take their solemn oaths.

Monsignor Guido Marini, the pontifical master of ceremonies, will then declare "extra omnes," alerting all non-cardinals that they must leave so the Conclave can be sealed.

The Maltese Cardinal Prospero Grech will then preach a reflection on the seriousness of what the cardinals are about to do and emphasize that they should act for the good of the Church.

The first vote will come soon after that, shortly before 7:00 p.m. Fr. Lombardi does not expected smoke to be seen until around 8:00.