The standard markings for classified information include the overall classification marking, portion markings, and the classification authority block. These markings are used to alert holders to the presence of classified information, identify the specific information needing protection, indicate the level of classification, and provide guidance on downgrading and declassification. Marking is the principal means of informing holders of classified information about specific protection and is the specific responsibility of the original and derivative classifiers
. Marking classified information is essential for alerting the holder to the presence of classified information, identifying the information needing protection, and indicating the level of classification assigned to the information. It also provides guidance on downgrading and declassification
