Definition of "OSI"

OSI

proper noun
1. (networking) Initialism of Open Systems Interconnection. An International Standard ISO/IEC 7894:1994(E) subtitled Basic Reference Model. A four-part document that contains a formal description of an idealized computer network architecture. The document is also published as ITU-T Recommendation X.200
2. (aviation, travel industry) Initialism of Other Supplementary Information. A message sent to an airline by an agent, in a standardised format, advising relevant information such as being a VIP, language difficulty, or passport information.
3. (software, organisation) Initialism of Open Source Initiative.
4. (US politics) Initialism of Office of Special Investigations.
  Quotations
  More recently the U.S. Department of Justice’s Office of Special Investigations (OSI), which is responsible for prosecuting Nazis and collaborators alleged to have entered this country illegally, closed out an investigation of Poppe’s immigration to the United States without bringing any charges against him. This action was taken in part because the OSI determined that Poppe had disclosed his relationship with the SS to U.S. intelligence prior to his immigration, thus making it highly unlikely that the OSI could successfully prosecute Poppe for illegal entry into the United States.
  2014, Christopher Simpson, “nine”, in Mark Crispin Miller, editor, Blowback: America’s Recruitment of Nazis and Its Destructive Impact on Our Domestic and Foreign Policy‎, New York: Open Road Media, published 1988, page 85