I designated shelves in the refrigerator and shelves in the kitchen cabinets for their exclusive use.  

We have two of everything as a backup like you, extra washers, dryers (gas and electric), stoves (gas and electric), refrigerators, dishwashers, sofa beds, modems, televisions and repair parts for all the previous items.We don't charge a cleaning fee because most of our tenants leave them fairly clean. 

The licensing has to do with use/disposal of refrigerants.

Make sure you've got their Social Security number, and a clause in your lease that mentions "liquidated damages", which is legalese for, "we both agree that the refrigerator is worth $3,000, etc".

I've heard they appraise and depreciate items not typically depreciated like stoves and refrigerators but items like light fixtures, water heaters, furnaces and all the wiring and plumbing attached to those items, sheds, the list goes on and on.

What would you do if the refrigerator in your rental went out and the tenant just bought about $200 of groceries and they all spoiled?

I would also have a check out list that is room specific--make them know what details you want looked at--we got back a new refrigerator with two cracked crisper baskets ($56 each) because the manager just opened the frig to see if it was clean, but did not see what we did--I made them charge the tenant for both to be replaced.

There's really a lot, including the entire refrigerator and kitchen, baths, showers, toilets, and most of the mini-blinds.The floor has not been cleaned beyond what I did: there are areas of grease, dirt, and debris throughout the house, including along the walls.

In fact, when low income tenants leave, they USUALLY leave a refrigerator and all the cabinets FULL OF FOOD (along with their never used broom and vacuum cleaner)!

I am renting out my 4 bedroom house in San Diego, should I include the washer, dryer and refrigerator in a house rental.