the tiltle might be a tad misleading, but could it be possible that when magical couples get married that their legal binding be some sort of spell that had to be performed? perhaps if there was an officiator/pastor type person at the ministry of magic to perform it for them, then their union would be automatically registered with the ministry?
it would be very similar to the unbreakable vow in a way, but not as finite (or else it's really death do us part and i don't think everyone's cool with that). i imagine that if someone cheated the vow would weaken, and should the couple choose to separate then the spell might totally disintegrate over time. i do remember there being some interest in divorce attorneys a while back, so maybe divorce proceedings could be a ministry official undoing the spell with all the implications that came with it? just spitballing at this point >>
i guess my question is would any of this be feasible as per mh canon? i'm not saying that this would totally override traditional marriage documents, but by the books most of the married couples were in it for the long haul, so i was thinking maybe there was a more permanent method.