Question

the military code - talking system refers to
strict rules about how soldiers behave.
secret languages used for communication.
the special technique of pronouncing letters and numbers.
the chain of command ranking structure of the armed forces.

Explanation:

Military code - talking systems are secret languages used for secure communication in the military to prevent enemies from understanding messages. They are not about soldier behavior rules, pronunciation techniques, or command - ranking structures.

Answer:

secret languages used for communication.