Jan 28, 2025
SI — "Special Intelligence" — the general category of sensitive compartmented information that deals with the sources and methods of signals intelligence collection. You'll notice that most of the documents leaked by Snowden are marked TOP SECRET double-forward-slash SI, or sometimes "COMINT," which is interchangeable. To read that document, a person with a TOP SECRET clearance needs to be eligible for the "SI" compartment, have signed a non-disclosure agreement specific to that compartment, and have a need to know about how, in general, signals intelligence works.
