Which series of government security standards does the orange book belong to?

The orange book is part of the Rainbow Series, which is a collection of government publications that establish standards for computer security and evaluate the security features of computer systems. Specifically, the orange book refers to the Trusted Computer System Evaluation Criteria (TCSEC), which outlines a set of requirements for classifying and evaluating the security features of operating systems. This was crucial during the time when the U.S. Department of Defense was focused on ensuring that computer systems used in military applications met certain security standards.

The designation as part of the Rainbow Series indicates a structured approach to security classification, with each "book" representing a different standard or set of criteria (e.g., the orange book for TCSEC, the green book for the Trusted Database Management System Evaluation Criteria, etc.). This comprehensive framework has significantly influenced security practices and evaluations in both military and civilian sectors, making it foundational in the field of operating system security. Other series mentioned do not represent recognized standards within this context, emphasizing the unique status of the Rainbow Series in the landscape of computer security guidelines.