What required voltage marking is placed on service equipment rated at 1000V or less?

The correct choice indicates that service equipment rated at 1000V or less must be marked with the statement "suitable for service equipment." This marking is important as it clearly communicates to users and technicians that the equipment conforms to safety and performance standards for installation and maintenance in a service capacity. This ensures that anyone using or working on the equipment understands the voltage constraints and its suitability for safe operation.

The emphasis on this marking helps to mitigate risks associated with electrical hazards, ensuring that personnel working on or near the equipment are aware of its operational limits and the nature of its service capability. This kind of labeling is critical in promoting safety and preventing misuse of the equipment in applications for which it is not designed.

While other markings such as voltage ratings, manufacturer information, or safety instructions are also important, they do not specifically address the equipment's suitability for service roles, making the marking about being "suitable for service equipment" the most relevant in this context.