Protection of privacy is a key issue in determining the extent to which archival materials are to be made accessible to the public. But what is informational privacy; i.e., what are the elements of information found in any type of document or database that must be withheld to avoid intruding on the privacy of an individual? This essay first examines post-World War II international statements that reference privacy. Then it turns to statements referring to privacy issued by the International Council on Archives (ICA), the worldwide professional organization that represents the archival profession to UNESCO. Third is a brief look at several 21st century academic considerations of privacy, one each by a lawyer, a philosopher, and an historian. Finally, it outlines some of the contextual elements that help archivists manage sensitive materials, even without a final definition of informational privacy.