av8 you want clues? ...
I saw this on the taxiway at DFW right before the threshold (of the southbound runways on the East side)
It was black on yellow, maybe with a black border, about say two foot (sorry 50cm) square, painted on the taxiway tarmac, just before the threashold. There were at tleast two of them I think.
I like Narrow Body though, like on the tube when they have a series of numbered signs and if you have that many cars in your train, you stop at the appropriate sign.