Wind Mitigation Course QUESTION

I am retaking InterNACHI’s Wind Mitigation course…
In the hurricane shutter section I just read this statement:
“The use of plastic honeycomb-style shutters has become popular due to their light weight and relatively low cost. It is important to note that some of these products are not impact-rated or approved, while others do meet the requirements of the Florida Building Code. It is critical to be sure, when inspecting this type of product, that the homeowner provides proof of product approval. This proof should be in the form of a Florida Building Code or Miami-Dade County Product Approval Document. A statement from the manufacturer stating that the product was “tested in accordance with ASTM E 1886 & ASTM E 1996” or something similar is not acceptable.”

I do not understand why this last part would say “not acceptable.”

Thanks everyone!!