I have been studying the schedule for the Circumvesuviana train and have not been able to figure out the letter codes that are the column headers for the schedule. The codes are 'D', 'DD' , and 'FER'. I assume 'FER' is Feriale, what do the D and DD signify?
The timetables I have show: F = Solo feriali - Working days
DD = Direttissimo - Direct No code D. The direct trains do not stop at all the stations, so the journey is somewhat shorter.
I am looking at the timetable here: http://www.vesuviana.it/web/files/Napoli%20Sorrento%20A4.pdf It has 'D' and 'DD'. I guess 'D' just means 'non-directissimo' as it does make more stops. Do all of the trains on this timetable run daily if not marked as 'F'?
Yes, I would assume, if there are no other codes, then those not marked FER, run all seven days, with those marked FER only running M-F. Other codes would be a cross or other letter abbreviation indicating it only travels on Sunday or Holidays.