Been to that site before and it seems to be the most reliable info out there - primarily because it cites specific references that can be verified (and is the work of an attorney). It should matter to whoever might accost you but I wonder if they'll bother to read it and, if they do, if they'll care. What you may to hear is "I don't care, anybody can post anything they want on the internet, it doesn't make it so". You may be better served to have copies of the documents it references (including header info).
I ride motorcycles. For safety, federal law allows motorcycles to have modulated headlights if they meet the required specifications (e..g., they alternate between 17% and 100% intensity, are not used at night, alternate at 240 cycles/second, etc.). The law was carefully written to pre-empt any state or local laws. However, many LEOs see them as "flashing lights" which are not allowed by most jurisdictions except on emergency vehicles. The result is a lot of citations being written for having modulated headlights that were specifically legalized. It was so bad that the manufacturers of these devices often included copies of the law and certificates of compliance which they obtained fromn the US Department of Transportation with their products - for users to carry with them. And still some who have these perfectly legal lights get citations and wind up having to go to court (where, as far as I've heard, the citations are dismissed).
The parallel should be obvious. It shouldn't be this way, but the reality is that sometimes you can be 100% in the right, but still have to deal with the hassle of proving that you are.
