This from Citizen Smith...
Once there was a mirror on a pole on a platform.
Then bits of it were painted yellow, then a small fence was put up round it. Bits of the fence were also painted yellow.
Then someone realised the fence meant that anyone passing the mirror might walk in an area behind a yellow line.
They put up signs so that people walked the other way. They made sure these signs were branded.
Great Western Route and FGW - delivering a Value for Money railway...