I'm netting out the answers as "any product that needed to be
kept cool" - as in you didn't want it to be inside a normal box
car where the sun could heat up the car. So "cool" was a relative
term. But they were also for shipments that did not require the
cooling of a reefer. But you also didn't want them to be in direct
sun ("too ripe").
I'm speculating that melons/etc. also might have benefited
from a little extra "controlled ripening" during transit due to the
limited exposure to outside air provided by the ventilated cars.
As always - this list is a treasured resource.
- Jim B.