G11B 11/11

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, {e.g. of electrons or X-rays} other than a beam of light {or a magnetic field} for recording