To which signals does the rule regarding communication NOT apply?

The rule regarding communication specifically does not apply to fixed signals. Fixed signals are permanent indicators that display information to train operators about track conditions, speed limits, and other important operational details. These signals are designed to be clear and unchanging, providing consistent guidance without requiring additional communication from operators.

In contrast, temporary signals often relate to work zones or changes in standard operations, which may necessitate clear communication to ensure safety and proper adherence to the altered protocols. Verbal signals play a crucial role in communication between crew members and during more dynamic situations, while emergency signals are also designed for urgent situations and require immediate recognition and response, emphasizing the importance of effective communication. Since fixed signals are not meant to change and do not depend on external communication for their meaning, the rules surrounding communication do not apply to them.