Which of the following is NOT a type of Naval message?

Permanent Communication Messages is not recognized as a legitimate type of Naval message. In naval communications, messages are categorized based on their function and urgency, with well-defined types serving specific purposes.

General Service Messages are used for routine communications within the naval service, handling a wide array of operational and administrative messages. Defense Special Security Communications Systems refers to secure communication channels designed for sensitive military information, ensuring that classified data can be transmitted safely. CRITIC messages are used for urgent communications that require immediate attention, often involving critical threats or situations.

The term "Permanent Communication Messages" does not align with established communication types within naval practices, likely contributing to its designation as the incorrect choice.