Which document must derivative classifiers refer to for guidance on classification?

A Security Classification Guide (SCG) is the correct reference for derivative classifiers as it provides specific guidance on how to classify information derived from original classified sources. The SCG outlines the criteria for classification, including the levels of classification and the handling instructions that must be adhered to when creating derivative classifications.

The SCG contains details on the elements of information that require classification, ensuring that derivative classifiers make informed decisions that are consistent with the original classification. It serves as a critical resource for understanding how to apply classification standards, helping to maintain compliance with regulatory requirements and support national security interests.

In contrast, an Operational Manual, DoD Directive, or Training Manual may provide useful information but do not specifically serve as the authoritative guidance for making classification decisions in the context of derivative classification. An operational manual might focus on procedures, a DoD Directive could address broader policy issues, and a training manual may cover general training guidelines without the precise classification instructions provided in an SCG. Thus, the SCG is essential for ensuring accurate and consistent classification practices.