Comment by vel0city

While the messages are not encrypted, you just have your actual message coded. Have agreed on phrases and what not discussed out of band. Send dummy messages to throw people off and not know what is a real transmission or a dummy one. Is that numbers station just spouting gibberish or communicating with spies?

The market closes at 5, dinner at the hotel, Grandpa will bring home the wine, bring your hat. Charlie 5 Alpha 2 4 7 3 Bravo. Maybe this is just discussing someone's evening, maybe its coordinating a group action.