What is an example of a mandatory directive?

The EC-1 form represents a mandatory directive because it is a formal document that provides essential instructions that must be followed by the railroad employees. These directives often involve safety protocols, operational procedures, or compliance measures that are critical to maintaining the safety and efficiency of railroad operations. The EC-1 form typically outlines specific actions or requirements that employees are obligated to implement in order to adhere to established regulations and standards.

In contrast, options such as general notices, system updates, and operator memos generally serve as informational updates or guidelines rather than binding orders. While they may contain important information, they do not carry the same level of mandatory compliance as the EC-1 form, making the latter the correct example of a mandatory directive in this context.