Green flags or class lights means that there is another train section following.
If a train has to be doubled, the first section would show green flags/lights (and the second one none as usual). Or if more than two sections, each section but the last one would carry green.
If a train has to be doubled, the first section would show green flags/lights (and the second one none as usual). Or if more than two sections, each section but the last one would carry green.