In Rule 171 and Rule 271 territory, which of the following is NOT required to designate a train?

In Rule 171 and Rule 271 territory, the identification of a train is essential for safety and operational efficiency. The correct answer emphasizes that designating a train does not require information about the engine weight and length.

While job symbols, lead engine numbers, and company names or initials are critical for clearly identifying the train and ensuring proper communication and coordination among rail personnel, engine weight and length do not play a necessary role in the basic identification process. This is because weight and length may be more relevant for logistical operations and physical clearances but are not crucial elements in the logistical communication needed for designating a train's identity in the operational context covered by Rules 171 and 271.

Thus, even though the other elements serve important functions within train operations, the specific requirement for designation focuses on aspects directly tied to identifying the train for service and procedural purposes, excluding engine weight and length from that critical list.