The letters are : These letters ( except `` Y '' and `` Z '' ) did not usually apply to passenger-rated but goods carrying vans ( e.g. parcels vans , horse boxes , milk and fish vans ) .
The letters used are : These letters ( except for `` Y '' and `` Z '' ) did not usually apply to the wide variety of passenger-rated but goods carrying vans ( e.g. parcels vans , horse boxes , milk and fish vans ) .