As set forth in Executive Order 12065, official information or material which requires protection against unauthorized disclosure in the interests of the national defense or foreign relations of the United States (hereinafter collectively termed “national security”) shall be classified in one of three categories: Namely, Top Secret, Secret, or Confidential, depending on its degree of significance to the national security. No other categories shall be used to identify official information or material as requiring protection in the interests of national security except as otherwise expressly provided by statute. The three classification categories are defined as follows:

(a) Top Secret. Top Secret refers to that national security information which requires the highest degree of protection, and shall be applied only to such information as the unauthorized disclosure of which could reasonably be expected to cause exceptionally grave damage to the national security. Examples of exceptionally grave damage include armed hostilities against the United States or its allies, disruption of foreign relations vitally affecting the national security, intelligence sources and methods, and the compromise of vital national defense plans or complex cryptologic and communications systems. This classification shall be used with the utmost restraint.

(b) Secret. Secret refers to that national security information or material which requires a substantial degree of protection, and shall be applied only to such information as the unauthorized disclosure of which could reasonably be expected to cause serious damage to the national security. Examples of serious damage include disruption of foreign relations significantly affecting the national security, significant impairment of a program or policy directly related to the national security, and revelation of significant military plans or intelligence operations. This classification shall be used sparingly.

(c) Confidential. Confidential refers to other national security information which requires protection, and shall be applied only to such information as the unauthorized disclosure of which could reasonably be expected to cause identifiable damage to the national security.