The invention relates to a value document, such as a banknote (1), which includes one or more window zones (2A, 2B) with one for example optically active element each which rotates a polarization plane P.sub.0 of polarized light L.sub.A, L.sub.B, penetrating the window zone by a defined angle. If such value documents are stacked and polarized light penetrates the superimposed window zones, the number of stacked value documents can be determined by way of the overall rotation of the polarization plane P.sub.A, P.sub.B. The overall nominal value of a stack of banknotes can thus be determined. The window zones can have category-specific rotational characteristics for different categories or nominal values and/or can be disposed in category-specific positions in the valuable document.