Aside from Scherer, other leading Latin American possibilities include Argentine Cardinal Leonardo Sandri, 69, head of the Vatican's office for Eastern rite churches, Jorge Mario Bergoglio, the Archbishop of Buenos Aires, and Brazilian Cardinal Joao Braz de Aviz, 65, who has earned praise as head of the Vatican's office for religious congregations.

NPR: Brazil Papal Contender: Place Of Birth Irrelevant

This is obligatory for priests of the main Roman church (but not for former Anglican clerics, or for most of the priests in Eastern-rite churches that also come under papal authority).

ECONOMIST: Paedophilia and the Catholic church

The Chaldeans are Eastern-rite Catholics - autonomous Churches of Eastern origin which retain their own liturgy and traditions, but recognise the Pope's authority.

BBC: Guide: Christians in the Middle East