Which classification marking appears at the bottom of the first page and provides details about the classification?

The classification marking that appears at the bottom of the first page and provides details about the classification is known as the classification line. This marking is crucial as it states the level of classification (such as Confidential, Secret, or Top Secret) and includes any applicable classification guidance, the declassification date, and the agency's identifier.

The purpose of the classification line is to provide clear and immediate classification details to the reader, facilitating proper handling of the document according to its designated security requirements. This marking helps ensure that individuals who interact with the document understand its sensitivity and how to manage it appropriately to safeguard national security interests.

While other markings, like footer marking and portion marking, serve different roles—footer marking might denote the document's title or page number, and portion markings categorize parts of the text—the classification line specifically provides a central point of reference for the document's overall classification status.