Which IFF modes are military?

• A. 1,2,3
• B. 0,1,2
• C. 2,3,4
• D. 1,3,4

Answer: (A)

The important idea is that IFF has specific modes tied to military identification and mission coding. Mode 1 carries a mission code, Mode 2 provides a unit or aircraft identification, and Mode 3 (the common identification mode) is widely used for general identification in many contexts, including military operations. Together, these three modes are the ones typically associated with military IFF functions in many training contexts, which is why the set listing 1, 2, and 3 is the best match. Modes 4 and 5 are newer cryptographic/authentication modes used for secure identification, and Mode 0 isn’t a standard IFF mode, so they aren’t part of the military set described in this question.