(2) whether the Successor Identification Friend or Foe System is compatible with the combat identification systems used by (a) the United States armed forces and (b) other NATO countries;
(3) what proportion of Army vehicles have been fitted with the Successor Identification Friend or Foe system; and what plans he has to fit systems to those which have not.
Successor Identification Friend or Foe (SIFF) is an airborne and maritime IFF system. It is not suitable for identification of ground vehicles, and therefore it is not fitted to any Army vehicles. SIFF is compatible and interoperable with the common standard of combat identification systems used by NATO countries, including the United States.