The Security Classification Guide (SCG) is part of the Program Protection Plan (PPP). It details how information will be classified and marked on an acquisition program. It’s the written record of an original classification decision or series of decisions regarding a system, plan, program, or project. The SCG addresses each Critical Program Information (CPI), as well as other relevant information requiring protection, including export-controlled information and sensitive but unclassified information. The Program Manager (PM) must develop a SCG in accordance with DoD Manual 5200.01. 
Information in the SCG is classified as either originally or derivatively.
- Originally: Original classification occurs when information is developed that intrinsically meets the criteria for classification under Executive Order 12958. Such classification cannot reasonably be derived from a previous classification decision still in force involving in substance, the same or closely related information.
- Derivative: Information under review is already known to be classified
AcqLinks and References:
-  Defense Acquisition Guidebook (DAG)
- DoD Manual 5200.01 “Volume 1 DoD Information Security program Overview, Classification and Declassification” – 24 Feb 2012
- DoD Manual 5200.45 “Instructions for Developing Security Classification Guides” – 6 April 2018
- DoD Instruction 5200.39 “CPI Identification and Protection Within RDT&E” – 17 Nov 2017
- DoD 5200.1-H “Handbook for writing a Security Classification Guide” – Nov 99
- Program Protection Plan Outline and Guidance – July 2011
- DoD Instruction 5200.01 “DoD Info Security Program and Protection of Sensitive Compartmented Info” – 9 Oct 2008
- DoD 5200.1ph “DoD Guide to Marking Classified Documents” – April 1997
- Template: Program Protection Plan (PPP)