Optically variable displayable / hideaway security elements for value and security documents

Value and security document having disposed thereon information elements (3) and an overlying cover layer (2, 2 ', 4, 4') which is opaque in a first functional state for a predetermined measurement method, and in a second functional state for the same measurement method permeable , and in this case, the information elements (3) are read out, wherein in the outer layer (2, 2 ', 4, 4') nanomagnetic particles (5, 5 ') are arranged, which are displaceable in the magnetic field and produce the second functional state.