G11B 11/105

Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups [CPC: G11B3/00] - [CPC: G11B7/00] or by different subgroups of group [CPC: G11B9/00]; Record carriers therefor using recording by magnetic means {or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field} using a beam of light or a magnetic field for recording {by change of magnetisation} and a beam of light for reproducing, {i.e. magneto-optical,} e.g. light-induced thermomagnetic recording, {spin magnetisation recording,} Kerr {or Faraday} effect reproducing