198025 ⎘
Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation , reproducing using an optical beam at lower power ; Record carriers therefor; Arrangement of the information on the record carrier, e.g. form of tracks, actual track shape, e.g. wobbled, or cross-section, e.g. v-shaped; Sequential information structures, e.g. sectoring or header formats within a track where the information is modified to form a visible pattern, e.g. forming a label by modifying the width of pits or grooves