What Is Not A Clue That The Oil Tank Is Buried Outside

Moved from forum help:::

It sounds like the professional opinion that after searching with a rod in the ground, looking for an inlet port, there was no evidence that there is one, but that someone has assumed there is one there.

Or it means someone asked and they did not even take time to look.

Well, the color of the window shutters is not a clue that the oil tank is buried outside.