What does 10-4 mean in OPP radio communications?

What does 10-4 mean in OPP radio communications?

• A. Acknowledgement; message received and understood.
• B. Unable to copy due to poor or no transmission.
• C. Stop transmitting; return to listening.
• D. In service; available for calls.

Answer: (A)

In OPP radio communications, 10-4 is the acknowledgment that a message has been received and understood. It’s the quick way to confirm to the sender that you heard them clearly and that you know what to do next, which keeps radio traffic efficient and reduces the need for repeats. This is different from signaling that you can’t copy a transmission, that you’re stopping transmission to listen, or that you’re simply in service and available for calls. Those statuses refer to other conditions or actions, not the explicit confirmation that a message was received and understood.

In OPP radio communications, 10-4 is the acknowledgment that a message has been received and understood. It’s the quick way to confirm to the sender that you heard them clearly and that you know what to do next, which keeps radio traffic efficient and reduces the need for repeats. This is different from signaling that you can’t copy a transmission, that you’re stopping transmission to listen, or that you’re simply in service and available for calls. Those statuses refer to other conditions or actions, not the explicit confirmation that a message was received and understood.