Timetable heading (de: Fahrplanüberschrift)

A heading would be nice for the tabular as well as for the graphic timetable viewer.

Typically the heading highlights large stations for the shown route. The start and end station would be the minimum.

railML does not provide a general string for this case, therefore the following selection is proposed.

1. Take the chosen train, nevertheless it's an operational (graphic timetable) or a commercial (tabular timetable) train. In both cases trains around this chosen train will be shown, but they are not considered for the heading.
2. Print train/@name if available.
3. Otherwise, print train/@description if available.
4. Otherwise, print start and end station:

ocp[@id = trainPart[@id = train/trainPartSequence[1]/trainPartRef[1]/@ref]/ocpsTT/ocpTT[1]/@ocpRef]/@name and

ocp[@id = trainPart[@id = train/trainPartSequence[last()]/trainPartRef[last()]/@ref]/ocpsTT/ocpTT[last()]/@ocpRef]/@name