http://en.wikipedia.org/wiki/Made_man

Traditionally, to become a "Made Man," the inductee had to be a male of 100 percent Italian descent. Former mob boss John Gotti changed this tradition in order to get son John "Made." Today, to become a "Made Man," the person has to be a Caucasian male of Italian descent on his father's side with his Italian surname. Some examples of "Made" members who are not 100 percent Italian include Junior Gotti, whose mother was of Russian and Jewish descent (she was adopted by her Italian-American stepfather which is why she has an Italian maiden name, DeGiogrio), and "Cadillac" Frank Salemme, former Boss of the Patriarca Cosa Nostra family in Providence, Rhode Island, who was half Irish. Chris Rosenberg was Jewish, and always wanted to become a member of the Gambino family, but couldn't because he was not of Italian descent on his father's side. Also, a "Made Man" is required to be involved in a murder, although murders committed for personal reasons “do not count”; he must have committed a killing contracted to him by a "Made" member.

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To become, "Made," the inductee is said to be required to take the oath of Omertà or, "silence." This ceremony allegedly involves the pricking of the trigger finger of the inductee, then dripping blood onto a picture of a Saint, typically St. Francis of Assisi or the Virgin Mary, which is then set alight in his hand and kept burning until the inductee has sworn the oath of loyalty to his new, "family", e.g., "As this card burns, may my soul burn in Hell if I betray the oath of Omertà." After the ceremony the inductee is now a "Made" man and a full member of the Mafia hierarchy, with certain responsibilities and privileges. The "Made" man now enjoys the protection of the Mafia establishment as long as he remains in favor and a previously agreed percentage of his criminal earnings are passed further up the hierarchy.
http://www.associatedcontent.com/art...en_in_the.html

For many years, only those of pure Italian decent were eligible to become made men. Even those born in those country had to be able to prove that all of their ancestors had come from Italy. This ethnic qualification excluded many of the people with whom the Mafia did business. It was ultimately dropped by John Gotti so his son could be "made." Today, the requirement is that candidates only have to be Caucasian who is Italian on their father's side. Today, having an Italian surname is more important than actually being 100% Italian.
This interested me. Of course, this has criminal underpinnings and the relation to racial preservation is strenuous. Even so, it's like an example of cultural preservation at a local level. But it appears to have broken down after a couple of generations as Italian men took Jewish & Irish women as wives, so the requirements became relaxed. Perhaps it's a small lesson, that even concerted attempts to maintain racial discrimination will eventually break down when differing groups live in proximity to each other.