An information recording medium, an information recordingreproduction head, and an information storage device are provided for performing a track servo operation at a smaller track pitch than that conventionally used without reducing the widths of servo burst patterns. A client transmits an RTSP request to a server. The symbols are mapped in the start position. Another table stores any information that is unique to a PRL entry, as well as an indicator of which common record is associated with it. To avoid false triggering, a dual set of infrared light emitting and detecting sensor units works in conjunction with logic circuitry for reliable activation of an electrically actuated access device.