The Vatican has raised the idea of ordaining older married men as priests in the Amazon's remote areas where there is a shortage of clergy, in what could be a historic shift, the BBC's religion editor Martin Bashir reports.
The issue was raised in detail in Pope Francis' landmark Encyclical on the Environment - Laudato Si - published in 2015.
He wrote that the region was confronting such challenges that it "requires structural and personal changes by all human beings, by nations and by the Church".
The document outlines areas for discussion at the forthcoming Amazon Synod which will focus on the region in October; bishops and indigenous people from Brazil, Bolivia, Peru, Ecuador, Colombia, Venezuela, Guyana, Suriname and French Guyana are due to attend the event in Rome.
These nations comprise 33 million people and are the source of one-fifth of the world's fresh water, one-fourth of all oxygen and more than one-third of global forest reserves.
The Vatican says the region represents a pastoral and environmental challenge - but it is the scarcity of priests that the Church can directly address.
And so this 45-page document, drafted after input from bishops conferences and local communities, suggests that the Synod in October should consider the possibility of ordaining elderly married men, who are respected in their communities.
It refers to "proven men of character" to deal with the shortage of priests - and says they should be outstanding members of the local Catholic community, with grown-up families.
The document also calls for some kind of "official ministry" for women in the area, although it does not elaborate.
This would be a dramatic change given that the First and Second Lateran Councils of 1123 and 1139 explicitly forbade priests from marrying - so we are almost past 1,000 years since the Catholic Church has maintained male celibate priests.
Eliminating the prospect of marriage ensured that children or wives of priests did not make claims on property acquired throughout a priest's life, which thus could be retained by the Church.
It took centuries for the practice of celibacy to become widespread, but it eventually became the norm in the Western Catholic Church.
At the end of their conference, participants will vote on various articles in a final document, which will then go to the Pope, who will decide whether to make it an official Apostolic Exhortation based on the Synod meetings.
This is likely to raise the usual questions about whether Pope Francis is a reformer, battling to change the Church.
Back in 2013, he spoke about gay people not being marginalised, but integrated into society.
"If a person is gay and seeks God and has good will, who am I to judge?" he said.
Some progressives felt this was the sign of a Pope willing to change the Church's doctrine - but in fact he subsequently reaffirmed the Roman Catholic Church's position that homosexual acts were sinful, though accepted that homosexual orientation was not.
In 2009, the Roman Catholic Church did grant special admission for married Anglican clergy to join the priesthood, but in a different context.
Back then, Anglican traditionalists, who were opposed to the ordination of women, felt compelled to join the Catholic Church, which continues to maintain the priesthood as a solely male preserve.
This document is the basis for discussion of a pressing issue for Catholics in the Amazon region.
And it is worth remembering that when asked in January about ordaining married men, Pope Francis said he was personally opposed to any such change to the priesthood.