Sensitive Compartmented Information (SCI) Oxford Dictionary of the US Military:
Information and materials bearing special community controls indicating restricted handling within present and future community intelligence collection programs and their end products for which community systems of compartmentation have been or will be formally established; in short, a designated category of intelligence materials which by virtue of their means of collection or other extraordinary aspect of their nature required special handling and more than routine protection.
Ever wonder what kind of agreement you have to sign to gain access to America’s top secrets? You can read the full form you must sign before you are authorized access to Sensitive Compartmented Information (SCI). Below is a snap shot of paragraphs 3 and 4 that makes it very clear why the Pentagon and Panetta are not happy.
SCI is also called codeword information. Compartmentation adds a level of need to know in addition to clearance level. Only those with a special designation, obtained via a single scope background investigation (SSBI), may have access SCI.