Which of the following is prohibited regarding the use of the engine bell?

The prohibition regarding the use of the engine bell emphasizes the importance of using it judiciously. Excessive use without cause can lead to desensitization among passengers and nearby individuals, reducing the effectiveness of the signal when it is genuinely needed. Additionally, overuse can contribute to noise pollution, which is particularly critical in residential or crowded areas.

By reserving the bell's use for necessary occasions, such as signaling approaches or warnings, crew members ensure that the bell remains a reliable alert rather than just background noise. This practice enhances safety by maintaining the bell's authority as a warning device, making it clear when a train is approaching or motioning in a particular direction.

The other options do not reflect the established guidelines for bell usage. Using the bell only during daylight hours could prevent necessary warnings from being communicated during low visibility or nighttime situations. Using it near station platforms is typically required to alert passengers of an approaching train. Likewise, in foggy conditions, using the bell becomes critical to enhance safety, as visibility is compromised.