What type of information cannot be passed using the remarks section of a flight progress strip?

The remarks section of a flight progress strip is primarily intended for supplementary information that might assist air traffic controllers in managing the flight. It includes details that aren't critical to immediate operations but could be useful for context or reference.

Control information generally relates to instructions and commands that need to be communicated clearly to ensure the safety and efficiency of air traffic management. This type of information, like clearances or instructions for altitude changes, needs to be communicated through more formal channels, such as voice communication or directly on the flight progress strip itself, rather than through remarks. The use of the remarks section for control information could lead to misunderstandings or missed critical instructions, thereby impacting safety.

In contrast, the other types of information listed can appropriately be included in the remarks section. Weather information can provide relevant situational context, pilot communications often relay crucial updates from pilots, and flight plan amendments may give updates on flight routes or operational changes, all of which can enhance situational awareness and support effective decision-making by controllers.