Power cord must be:
1.UL rated
2.Originally supplied, or meeting same specs as original
3.Long enough to reach your units easily ie. no tension
4.Connected to a good quality surge protector (unless your stereo is a cheaper crap than the power cord itself ;) )
Not sure if you're being serious or sarcastic. Tone of voice and humor can be difficult to convey on the computer screen. But I'll address each of your points.
1. Most aftermarket cables aren't UL listed because the certification process is costly. UL standards helps ensure mass produced cables meet minimum safety requirements for fire safety and electrical shock protection. It is a risk management tool for very large corporations. Low volume, boutique cables cannot justify the expense of a UL listing. That doesn't mean their build quality or safety is sub-par.
2. Which specs? Same LCR? Same quality and type of conductor material, number and gauge of conductors, layup design geometry, filling interstices, tape barrier, mechanical and electrical shielding, outer jacket? What about connectors?
3. This is a huge variable from system to system. Which is one reason why aftermarket cables are prolific.
4. I know many people who run amps directly to the wall receptacle w/o any surge protection devices. Some more experienced friends' systems use whole home surge protection device
installed at the main electrical service panel or a sub panel. They're not cheap. Many of my hifi friends use that in addition to dedicated 20 amp circuits for each device, quality receptacles, balanced power transformers or AC regeneration devices like PS Audio Power Plant. Most would agree that MOV based surge protectors do the sound quality no favors.