In which situation can a document not be classified?

A document cannot be classified if it has been publicly disclosed because classification is primarily intended to protect sensitive information from being shared with unauthorized individuals. Once a document is public, the information it contains is no longer considered sensitive or needing protection under classification guidelines. Public disclosure means that the information is available to anyone, eliminating the necessity for classification to maintain its confidentiality.

In contrast, outdated documents may still contain sensitive information even if they no longer reflect current realities, and opinions may still be relevant enough to warrant classification depending on their nature and context. Similarly, information based on unconfirmed sources may still need protection until assessed and verified, regardless of its reliability.