In terms of etiquette? "Permanently" is simply wrong. Correct flag etiquette means raising it in the morning and lowering it in the evening, as well as during inclement weather. Or while engaged in battle, and a few other unusual circumstances.
The modern habit of flying a flag 24x7, lighted at night or not, and just letting it shred in the wind, to me in disrespectful jingoism, not to be confused with flying a flag. If you want it to be there "always" then you paint it on the mast or hull--rather than flying one.