Which document should be the primary source for derivative classification guidance?

The primary source for derivative classification guidance is the Security Classification Guide (SCG). The SCG provides specific instructions on how to classify information based on existing classified materials and outlines the parameters for derivative classification. It serves as an authoritative reference that helps individuals understand which aspects of the information need to be classified and how to appropriately mark classified documents according to established standards.

By using the SCG, personnel ensure that they are following consistent and authorized processes for classification, minimizing the risk of unauthorized disclosure and correctly managing sensitive information. Other options, while potentially informative, do not serve the same focused and comprehensive role as the SCG in derivative classification practices.