What is the difference between hotelCode and hotelCodeSupplier?

Normaly both should coincide as we do not have our own hotel codes. But sometimes, there are Sellers that return the same hotel code for different properties. In those cases we concatenate the destination code with the hotel code in order to make the code unique.

Being that said, hotelCode will be the one returned through our API (concatenated if needed) and hotelCodeSupplier will be the native code of the supplier.

You should always map the hotelCode code since  it will be the one you should use to perform the searches.