This invention allows the user to insert an entry point (bookmark) at an arbitrary
recording position of video data, audio data, and the like as if he or she placed
a bookmark between pages of a book. Information RTR_VMG that manages recorded objects
includes movie cell entry point information M_C_EPI. M_C_EPI includes entry point
playback time information EP_PTM and text information PRM_TXTI that pertains to
an entry point. PRM_TXTI can store text information that pertains to its contents
together with type information and date information of an entry point.