What is a key element in transmitting non-essential messages to air traffic control?

The correct choice emphasizes that all communications with air traffic control must prioritize air safety, which is the fundamental responsibility of both pilots and air traffic controllers. Non-essential messages should still be relevant to the safe operation of flights. This means that, even if the message is not critical, it should still pertain to information that could impact safety or operational efficiency.

In aviation, every piece of communication is important and should focus on clarity and relevance to the overall safety and effectiveness of air traffic management. Therefore, it's essential that even non-essential messages do not detract from or interfere with more critical safety communications.

The option regarding confidentiality, while important in other contexts, is less relevant for non-essential messages since operational integrity and clarity must always come first. Creative language could introduce ambiguity, which is counterproductive in air traffic communications where clear and standardized language is crucial. Limiting messages only to emergencies would ignore the need for operational efficiency and situational awareness, which are also vital aspects of safe flight operations.