SI is the SCI control system marking abbreviation for which SCI control system?

• A. Special Intelligence Control System
• B. Security Information Control
• C. Sensitive Information Control System
• D. System Integrity

Answer: (A)

In SCI, access isn’t just about a clearance level but also about compartment marks that gatekeep specific kinds of information. The SI marking stands for Special Intelligence and designates the Special Intelligence control system compartment. It signals that the material comes from Special Intelligence sources and requires the right SCI clearance plus access to the SI compartment. The other options don’t correspond to recognized SCI control systems, so they don’t fit as the meaning of SI.