What does the phrase "over" signify in radio communication?

In radio communication, the phrase "over" is used to indicate that the transmission has ended and that the speaker is inviting a response from the receiving party. It is a clear cue that the sender has finished their message and is now awaiting a reply. This protocol helps to ensure that communications remain organized and understandable, especially in situations where multiple parties may be communicating over the same frequency.

Understanding this concept is crucial in maritime operations where effective communication can directly impact safety and efficiency. The other options either refer to different aspects of radio communication protocols, such as the lack of a request for feedback or clarity issues, but specifically, "over" is solely concerned with signifying the end of a transmission and inviting a response.