Supplement/surcharge & seat reservation requirement info should be shown (NL)
In the Netherlands, depending on your particular connection a railway trip may require an additional supplement/surcharge on top of your standard fare ticket(s). Currently KTrip does not warn the user about this, but the data should already include the information so KTrip should "just" display it.
Good examples to test with:
- From Rotterdam Centraal to Amsterdam Centraal: watch out for ICD train/service codes, because these indicate a supplement..
- From Arnhem Centraal to Utrecht Centraal/Amsterdam Centraal: watch out for ICE International services.
Note that this cannot simply be inferred from train/service codes, for example while a supplement/surcharge is required on ICDXXX services between Rotterdam Centraal and Amsterdam Centraal, there is no such supplement/surcharge for the same service continuing from Rotterdam Centraal on to Breda.
Similarly, while reservations may be required for Thalys and Eurostar services calling at Amsterdam Centraal, Schiphol Airport and Rotterdam Centraal, there is no such requirement for Intercity Internationaal from Den Haag Centraal/Amsterdam Centraal to Brussel Zuid/Bruxelles Midi (and IIRC you do not need a seat reservation either for the ICE International services to/from Amsterdam Centraal while travelling in the Netherlands).