All returned properties from reverse lookup.

I am currently looping through all returned properties and writing them to a DB with the key as row name and the value as the rows value.

However, it seems that every time I use it in a new area there are new properties appearing, which means my db table does not have a row for them:

"address": {
"supermarket": "Billa",
"road": "Marxergasse",
"suburb": "Erdberg",
"city_district": "Landstra\u00dfe",
"city": "Gemeinde Wien",
"county": "W",
"state": "Vienna",
"postcode": "1030",
"country": "Austria",
"country_code": "at"

}

So, is there in the documentation a place where I might find all of the possible properties? Tried looking but couldn't find anything sadly.