Foreword-2

Based on the names of the clauses, the reader can also get an idea of what to focus on in each clause. Most end-product standards can actually be read through the table of contents to get a general idea. For inexperienced users of the standard, we recommend that when you see the clause names, you actively think about the hazardous situations that may be involved in that topic; for experienced readers, the table of contents is actually a quick window into the standard. Most IEC standards have a similar textual structure, mainly in the six clauses from the first to the sixth, which are all on the same topic. Subsequent clauses, because of the different products, the corresponding requirements are different, and therefore focus on different topics. From a safety point of view, all the clauses listed in this standard can be uniformly categorized in order to prevent the following five types of risks, i.e., electric shock, thermal injury, mechanical injury, fire hazards, and radiation or chemical hazards. The standard divides the clauses according to the structural features and functions of the product. Appendices-Annex can be regarded as subsidiary clauses to the main clauses, which can be more detailed and specific requirements for the main clauses (such as Appendix B and Appendix S), or detailed explanations and definitions for the main clauses (such as Appendix K and Appendix M) or guiding operational guidelines (such as Appendix O and Appendix Q). Their contents are not decisive for the understanding of the standard.