United States special operations forces (SOF) are the special forces of the United States Department of Defense’s United States Special Operations Command (USSOCOM) within the United States Armed Forces, used for special operations. DEVGRU is most definitely NOT the most classified unit in the US Armed Forces and the United States overall. Neither it is the Delta Force, CAG, The Unit or whatever you want to call it. From my perspective, currently, the most secretive unit is CIAs SAD, of course, from the list of the units ever mentioned.