How to understand the ninth paragraph of INTRODUCTION

The ninth paragraph of introduction as below:
An appliance employing materials or having forms of construction differing from those detailed in the requirements of this standard may be examined and tested according to the intent of the requirements and, if found to be substantially equivalent, may be considered to comply with the standard.

Since the standard lags behind the product, the applicable material or structure in the product may not have a corresponding clause or requirement, in which case the intent of the standard can be used to determine and test. For example, the principle of double protection can be used to determine, as well as the principle of single failure to carry out abnormal testing; and then decide whether to comply with the standard requirements. Of course, for beginners, it is difficult to grasp the degree of which, it is recommended to ask more people to discuss or ask senior engineers to give advice when making the corresponding assessment.

Personally, I think this is the most important sentence in the INTRODUCTION section. When we have a hard time deciding if we are going to enforce the requirements, or can’t decide on the severity of the enforcement of the standards. We need to think about the “intent of the requirements”. You will find that the requirements in the standard are derived from the actual conditions of use of the product as well as reasonable conditions of misuse, and you need to guess that a requirement in the standard is modeling that condition of use or reasonable conditions of misuse. I think you then get a relatively reasonable method of implementation.