What is a key feature of the Non-secured Mode in communication?

A key feature of the Non-secured Mode in communication is that all radio calls are sent, heard, and interceptable. This mode operates without any security measures such as encryption, meaning that anyone with the appropriate receiving equipment can listen to the communication. In environments or scenarios where secure communication is not essential, Non-secured Mode allows for quick and straightforward exchanges, but it exposes the information being transmitted to potential interception by unauthorized individuals.

In contrast, the other choices involve aspects of secure communication. The presence of encryption, limitations to secure channels, and requiring authorization for calls are all elements aimed at ensuring confidentiality and protecting the integrity of the communication, making them characteristics of secured communication modes rather than Non-secured Mode. In summary, the distinguishing trait of Non-secured Mode is the complete lack of protective measures, rendering all exchanges vulnerable to interception.