Any of the AV devices or the users of a network system to which the present invention is applied can input detailed information on a recording reservation and provide the remaining AV devices and the users with the detailed information on the recording reservations that the AV device or the user has and it is possible to realize a means to be used by any of the AV devices or the users to provide the remaining AV devices and the users with the detailed information on the recording reservations that the AV device or the user has. Such a system can effectively avoid occurrence of so-called double booking and is easy to use for the users. In a specific processing operation, raw_text_information_block containing a raw text showing details of a reservation and character_code_information_block and language_code_information_block showing the coding of the raw text are described in a Resource Schedule Entry of an RSB.