Which of the following is an example of information categorized under "Special Categories"?

Sensitive Compartmented Information (SCI) is categorized under "Special Categories" because it involves sensitive data that requires specific handling and access controls due to the potential for significant harm to national security if disclosed. SCI refers to classified information concerning or derived from intelligence sources, methods, or analytical processes that need to be compartmented to protect it. This classification level is essential in intelligence communities where certain information must be segregated from broader classified material due to its increased sensitivity and the risks associated with its unauthorized disclosure.

On the other hand, the other examples, while they may be classified or sensitive in nature, do not fall under the official designation of "Special Categories" as described in classification guidance. For instance, confidential data about employee salaries is typically handled under personnel management and doesn't encompass intelligence-related information, while general operational procedures and information about public contracts do not require the same stringent compartmentalization or have the same implications for national security. Thus, the distinction of SCI as a member of "Special Categories" stems from its specialized handling requirements inherent to national defense and intelligence operations.