Some shore power connections are labelled. Look for one labelled 'air
conditioning' and disconnect that one. A good percentage of the time the
refrigerator, freezer or icemaker won't be on the same circuit as the A/C.
If you're inclined to check it'd certainly be polite to avoid disconnecting
the one that lets food in the fridge to go rotten. But most units are
designed to run both off AC and 12v and there's no way to tell which is
being used. So it won't do a lot of good to disconnect one of the lines and
then look in the fridge as it'll cut over from AC to 12v and keep right on
running. Wearing down the battery along the way, of course and then you're
putting the bilge pump operations at risk.

If it's got a label I'd just disconnect the one for the AC. I'm not sure
I'd go leaving notes about it.

-Bill Kearney