VATICAN CITY — The Vatican has revised how it evaluates purported supernatural events, such as reported visions of the Virgin Mary, to guard against hoaxes and account for news going viral.

Previous approved apparitions have turned these sites into major pilgrimage destinations, drawing millions of people to them each year:

— Our Lady of Guadalupe, Mexico: An Indigenous Mexican man named Juan Diego reported several apparitions of the Virgin Mary in 1531. For believers, the image of the Virgin that hangs in the basilica is a miracle itself, made when Juan Diego carried flowers in his cloak after receiving one of the visions, and upon opening it, found that the cloak displayed a detailed, colorful image of the Virgin.

— Lourdes, France: July 16 marks the anniversary of purported visions of Mary in 1858 by a young girl, Bernadette Soubirous, and the discovery of allegedly healing spring waters in southern France near the Pyrenees.

— Fatima, Portugal: The three shepherd children said the Virgin Mary appeared to them six times in 1917 and confided to them three secrets. The first two described an apocalyptic image of hell, foretold the end of World War I and the start of World War II, and the rise and fall of Soviet communism.

Some disputed Marian apparitions include:

-Medjugorje, Bosnia-Herzegovina: In 1981, six children and teenagers said they saw apparitions of Mary on a hill in the village of Medjugorje, and some of the original “seers” claim to receive continuous revelations. The Vatican has been studying the phenomenon for years, and officials said Tuesday a decision was expected soon.

—Our Lady of All Nations, Amsterdam: One of the most egregious cases of flip-flopping determinations by Catholic authorities over the course of 70 years about the supernatural nature of purported Marian apparitions. In 2020, the current bishop, with the backing of the Vatican, reaffirmed the 1974 negative judg­ment from the Vatican about the supernaturality of the alleged “apparitions and revelations.”

-Army of Mary, Quebec, Canada: After another flip-flopping by bishops, the Vatican in 2007 excommunicated the members of the Army of Mary after its founder claimed to have had Marian visions and declared herself the reincarnation of the mother of Christ.