Possible "class" and "type" values in Nominatim records

Hello, everybody.

There are keys “class” and “type” in records returned by Nominatim.

  1. What are possible values of these?
  2. Is there a query which would return all of them, something like in SQL would be “SELECT DISTINCT class FROM object”, “SELECT DISTINCT type FROM object”?

I need an exhaustive list of possible values, or perhaps a list which lacks some rarely used values, because I need to provide translations of these in the software I am developing.