Classification (National Security)
The system of designating information as Confidential, Secret, or Top Secret to protect national security, along with the rules for marking, handling, and eventually declassifying it.
In a national security context, classification is the formal designation of information whose unauthorized disclosure could damage national security. Under Executive Order 13526, information is classified at one of three levels — Confidential, Secret, or Top Secret — according to the degree of expected harm, and only authorized officials may classify it.
Classified records must be marked with their level and declassification instructions and safeguarded under strict handling rules. Classification is meant to be temporary: records are released through declassification — automatic, mandatory, or systematic review — when protection is no longer warranted. (This sense of “classification” differs from records classification, which means filing records against a file plan.)