Actually you can determine a lot about the camber of a wing which used to be single surface and then has the bottom filled in which I believe is what the question was about. The camber will very close to half of the original. The thickness will be much greater then the original but exactly how much greater is more difficult to tell.

The difficulty with trying to force people to use the current terminology for airfoil shapes is that the terms are not at all intuitive. If all you quote is maximum camber and maximum thickness you're saying almost nothing about the shape of the airfoil which is all people can see and identify with. Undercambered means something to most people, 6% camber with 8% thickness doesn't. It depends if we're talking to normal modellers or we only want to help qualifed aerodynamicists .

Steve