Which of the following does not contain mandatory requirements in the NEC?

Annexes in the National Electrical Code (NEC) serve supplementary purposes and provide additional information, interpretations, and guidelines, but they do not contain mandatory requirements. They typically include explanatory material or examples that help users better understand the mandatory rules outlined in the main sections of the code. This is an essential aspect of the NEC, as it distinguishes between rules that must be followed and those that are intended for guidance.

In contrast, the parts, sections, and tables in the NEC are structured to present requirements that are enforceable; they contain specific provisions that must be adhered to when designing and implementing electrical installations. Each of these components lays out the official regulations that are applicable to electrical safety and performance, ensuring compliance and safety in electrical practices. This distinction between the necessary and supplementary materials is critical for professionals working in the electrical field to grasp in order to successfully navigate the code and uphold safety standards.