I still cannot find a source for the law requiring DFCO, but since any idiot can modify Wikipedia, I went ahead!
I just copied it directly from our wiki. I will add information as I gain it. Hopefully someone with more information will contribute.
Curiously, it says there is not a user named Xist, until I tried to create an account.
https://en.wikipedia.org/wiki/User_t...n_fuel_cut-off