This Order prescribes a uniform system for classifying, declassifying, and safeguarding national security information. It recognizes that it is essential that the public be informed concerning the activities of its Government, but that the interests of the United States and its citizens require that certain information concerning the national defense and foreign relations be protected against unauthorized disclosure. Information may not be classified under this Order unless its disclosure reasonably could be expected to cause damage to the national security.
NOW, by the authority vested in me as President by the Constitution and laws of the United states of America, it is hereby ordered as follows:
(a) National security information (hereinafter “classified information”) shall be classified at one of the following three levels:
(1) “Top Secret” shall be applied to information, the unauthorized disclosure of which reasonably could be expected to cause exceptionally grave damage to the national security.