A label (1) made from a layer composite (15) includes at least
one
machine-readable diffractive bar code (3) consisting of narrow rectangular
fields (4) occupied by the optically active structures and intermediate
surfaces (5). The optically active structures which are covered by a reflection
layer are embedded between layers of the layer composite (15). The diffractive
relief structure used in the diffractive bar code (3) for the fields (4)
diffracts and polarizes incident light and scatters the diffracted light into a
half-space above the diffractive relief structure. A second diffractive relief
structure differs at least in respect of the polarization of the polarizedly backscattered
light with respect to the first diffractive relief structure. The second diffractive
relief structure can be used for example for field surfaces of a second bar code
in the bar code field (9) on the label (1) or for the intermediate
surfaces (5). The light which is polarizedly backscattered at the diffractive
bar code (3) can be detected by means of one of the known commercially available
reading apparatuses for bar codes produced by printing. The bar code produced by
printing can be used for individualizing the labels (1).
