Which NISPOM chapter may NOT apply to all facilities?

Chapter 4 of the NISPOM focuses on Classification and Marking, which deals with how sensitive information is classified and labeled. This chapter may not apply to all facilities, particularly those that do not handle classified information regularly or at all. Facilities that are involved in unclassified work or those that do not possess classified contracts may have minimal relevance to the rules outlined in this chapter. Understanding the classification process and its implications is crucial for facilities that deal with classified information, but those without such responsibilities may find this chapter unnecessary.

On the other hand, the other chapters, like General Security, Personnel Security, and Physical Security, establish protocols and guidelines that are fundamental to security operations in all facilities, regardless of their level of exposure to classified materials. Therefore, while the general principles of security apply broadly, the specific directives in Chapter 4 may not be relevant to every facility operating under the NISP, making it distinct in this regard.