For much of the Catholic Church’s 2,000-year-long existence, bodies of the faithful were destined for cemetery plots or mausoleum tombs. There you rested, unless you became a saint, in which case select remains ended up in more exotic destinations.

St. Catherine’s mummified head and ampules of St. Januarius’s blood were displayed in Italian churches as sacred relics. St. Anthony of Padua’s 800-year-old tongue toured New York in 2013. But completely incinerating the dead – which early Christians associated with paganism – was forbidden for saints and sinners alike.

In 1963, the Vatican loosened its long-standing prohibition against cremation. Dust to dust was acceptable again, with a few qualifications. Although the Catholic hierarchy maintained that burial was preferred, cremation was acceptable as long as “it does not demonstrate a denial of faith in the resurrection of the body,” according to the Catholic Catechism.

Fifty-three years later, in preparation for the Nov. 2 celebration of All Souls’ Day, the church further clarified what was appropriate for Catholic cremation. The Vatican, according to a document released Tuesday, would like to see the practices of scattered ashes or urns on the mantle vanish as so much smoke.

The rules come at a time when approximately half of deceased American’s bodies are cremated. In the United States, depending upon the location, cremation rates for Catholics may be as high as 40 percent. When burial costs rose and cemetery plots became rarer, the Catholic World Report noted in 2012, cremations became an attractive alternative to Catholics.

As the practice of cremation grew, so too did a few of the frowned-upon habits. Under the published guidelines, approved by Pope Francis in March, “the ashes of the faithful must be laid to rest in a sacred place.” Such places are mostly limited to cemeteries or certain church areas. “Only in grave and exceptional cases” can loved ones keep ashes in a domestic residence.

Warning against appearances of “pantheism, naturalism or nihilism,” the church does not permit anyone “to scatter the ashes of the faithful departed in the air, on land, at sea or in some other way, nor may they be preserved in mementos, pieces of jewelry or other objects.”

The Cremation Association of North America told Time magazine in 2013 that Americans were equally divided in the practices of keeping ashes, burying ashes and scattering ashes. In the United States, the legality of scattering ashes depends upon the remains’ final destination. The National Park Service requires a permit. Stadiums and theme parks discourage visitors from leaving loved ones behind, though it happens anyway. At sea, the U.S. Environmental Protection Agency states that cremated remains must be disposed at least three nautical miles from shore.

There is no such gray area for the church. “We come from the earth and we shall return to the earth,” Cardinal Gerhard Muller, head of the Congregation for the Doctrine of the Faith, told the Guardian. “The church continues to incessantly recommend that the bodies of the dead be buried either in cemeteries or in other sacred ground.”

The instructions left some observers feeling bitter. The Vatican, wrote Irish Independent columnist Liam Collins on Wednesday, “appears to have teams of under-employed civil servants with nothing better to do than dream up new ways to torment the faithful.” Irish crematoriums were also skeptical that Catholic families would abide by the new directives.

For Catholics looking to emulate Pope Francis’ climate-minded messages, such as his 2015 environmental encyclical “Laudato Si,” cremation may appear to be a greener alternative to the traditional formaldehyde-based embalming process. But as the Atlantic noted in 2014, cremation is not perfect, burning the fuel equivalent of two SUV gas tanks.

Of the most eco-friendly options, a method called green burial – which eschews formaldehyde embalming in favor of burial in a biodegradable shroud or plain cedar box – has generated a small but growing interest among Americans. Catholics, too, have taken note. In 2012, the Most Holy Redeemer Cemetery in Albany, N.Y., designated 260 meadow graves for green burial, one of the first U.S. Catholic cemeteries to do so.