The Authority having Jurisdiction, ultimately the local government often passes laws/bylaws that accept in full the NEC. They have to to have legal authority to enforce compliance. Lack of compliance is a civil violation not criminal but you are still breaking the law. Negligence can become criminal of course.
UL ensures a level of safety compliance and UL standards also have relevance to NEC. That power cord may not need to comply to UL, but it would likely need to comply with NEC (and your insurance policy). Outside the US, many countries require only conforming products to local standards. A UL is not good for "5 years". It is good till a new standard is released and while you maintain your listing.
I am curious about this internal distortion and dynamic loss of stranded conductors at audio frequencies science seems to have missed.
UL ensures a level of safety compliance and UL standards also have relevance to NEC. That power cord may not need to comply to UL, but it would likely need to comply with NEC (and your insurance policy). Outside the US, many countries require only conforming products to local standards. A UL is not good for "5 years". It is good till a new standard is released and while you maintain your listing.
I am curious about this internal distortion and dynamic loss of stranded conductors at audio frequencies science seems to have missed.