Which of the following is NOT one of the six aids to defend against analysis?

• A. Good procedures
• B. Callsign omission
• C. Authorized code words
• D. Use of plain language

Answer: (D)

Defending against analysis means hiding patterns and meaning in radio traffic so an observer can’t easily deduce who’s talking, when they’re talking, or what they’re saying. Good procedures help by standardizing operations, timing, and transmission order, which reduces predictable patterns that could be exploited. Callsign omission removes obvious identifiers, making it harder to track who is transmitting. Authorized code words replace plain speech with agreed-upon terminology, so the content isn’t immediately understandable to outsiders who don’t know the code. Using plain language, on the other hand, exposes the actual message and structure to anyone listening, making it easier to analyze. So plain language is not an aid to defend against analysis, which is why it’s the correct choice.