The Roman Catholic Church has banned the scattering of ashes of the dead, insisting that, in some circumstances, those who request it for themselves should even be denied a "Christian funeral".
Strict new Vatican guidelines forbid a list of increasingly popular means of commemorating loved ones - from scattering ashes at sea to having them turned into jewellery or put in a locket - dismissing them as New Age practices and "pantheism".
A formal instruction, approved by Pope Francis, even forbids Catholics from keeping ashes in an urn at home, other than in "grave and exceptional cases".
It also rules out the increasingly common practice of dividing people's ashes between members of the family.
The document issued by the Vatican's doctrinal watchdog the Congregation for the Doctrine of the Faith (CDF) claims many modern cremation practices increasingly reflect non-Christian ideas about "fusion with Mother Nature".
For centuries the Catholic Church forbade cremation altogether, primarily because of the teaching that Christians will be raised from the grave ahead of the Day of Judgment.
The ban was finally lifted in 1963 in a landmark Vatican document which accepted that there were often pressing social and sanitary needs for cremation but urged Catholics to choose burial wherever possible.
The new guidance accepts cremation in principle but signals a clampdown on increasingly varied uses for ashes, insisting instead that they should only be kept in a "sacred place", such as a cemetery.
"[The Church] cannot ... condone attitudes or permit rites that involve erroneous ideas about death, such as considering death as the definitive annihilation of the person, or the moment of fusion with Mother Nature or the universe, or as a stage in the cycle of regeneration, or as the definitive liberation from the 'prison' of the body," it argues.
It goes on: "In order that every appearance of pantheism, naturalism or nihilism be avoided, it is not permitted 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 jewellery or other objects."
It then adds that if someone has asked for their ashes to be scattered "for reasons contrary to the Christian faith" then "a Christian funeral must be denied to that person".
Four years ago the ashes of actor James Doohan, who played "Scotty" in Star Trek, were blasted into space, along with those of more than 300 others.
Earlier the remains of the journalist and writer Hunter S Thompson were fired from a cannon on top of a 150ft tower in Colorado.
Other have requested their ashes be mixed into fireworks, ground into gems for loved-ones or even turned into items such as a Frisbee.
Cardinal Gerhard Mueller, Prefect of the Congregation for the Doctrine of the Faith said there had been an "unstoppable increase" in cremation and that it would soon be the "norm" in many countries.
But he insisted: "The dead are not the private property of the family.
"The ashes of the deceased must be kept in a sacred place, either in a cemetery or in a church.
"Death is not the end our of our existence."
But Andrew Copson, chief executive of the British Humanist Association, whose members carry out thousands of funerals in the UK a year, said: "People memorialise people in all sorts of ways, I think what matters is that it respects the wishes of the person who has died and gives peace and healing to the people who are still alive.
"Whether you want to have someone's ashes put into a firework or scatter them in a favourite place or inter them in the ground I think that what matters is the wishes of the person who has died and the needs of the family and friends and those who are still alive.
"I don't think it is anyone's role to second guess or interfere with that."