The requirements for caution stickers regarding power lines are primarily guided by which standard?

The correct answer is based on the fact that the requirements for caution stickers regarding power lines primarily fall under the American Society of Mechanical Engineers (ASME) standards. ASME provides guidelines that ensure safety and proper awareness around the operation of cranes and other lifting equipment, particularly in relation to their proximity to power lines. These guidelines may include specifications for the design, placement, and visibility of caution stickers, which serve to inform operators and nearby personnel of potential hazards associated with electrical lines.

The other standards, while important in their own rights—such as OSHA which focuses on occupational health and safety regulations, ANSI which sets consensus standards for safety and performance, and ISO which deals with international quality standards—do not specifically address the caution stickers for power lines to the same extent as ASME does in the context of crane operations. Thus, ASME is the most relevant authority for this particular requirement.