An information management method and an information management apparatus can minimize the confusion and the degradation of signal quality that can arise in terms of the compatibility of an apparatus adapted to a set of new standards and another apparatus adapted to a set of old standards. The protection flag of track mode is made equal to 1 as protection information for protecting the recording area of a disk carrying strings of codes according to the new standards from recording, editing and erasing operations of an apparatus conforming to the old standards and adapted to be able to refer only the management data area of the disk. When the disk carrying strings of codes recorded according to the new standards is used by the apparatus conforming to the old standards, the recording area of the disk is protected from recording, editing and erasing operations of the apparatus conforming to the old standards as the protection flag is 1.