Which classification marking cannot be changed without a review?

The classification marking that cannot be changed without a review is "Top Secret." This is the highest level of classification and indicates that unauthorized disclosure could cause exceptionally grave damage to national security. Because of the sensitivity and potential consequences associated with Top Secret information, any alteration to its classification status requires a rigorous review process.

This review ensures that a formal assessment is made to justify any change, reflecting the importance of the information and providing the necessary safeguards to protect national security interests. Other classification levels, while still important, do not have the same stringent requirements as Top Secret and may allow for more flexibility regarding changes without necessitating a formal review process.