1. A distribution system for recording a copy of compressed audio content using variable-length encoding onto a recording medium and supplying the content to a playback apparatus, said distribution system comprising: a distribution server operable to distribute the content via a network; a first receiving apparatus operable to receive the content via the network, said first receiving apparatus comprising a first receiving unit operable to receive, via the network, a data set including the content and control information controlling copying of the content onto the recording medium, and to hold the received data set, and a recording unit operable to generate authorization information showing whether moving the data set to another receiving apparatus is permitted, and to record the content onto a distribution medium together with corresponding usage rule information including (1) the authorization information, and (2) the control information included in the data set; and a second receiving apparatus operable to receive the content via the network, said second receiving apparatus comprising a second receiving unit operable to receive the data set from said distribution server via the network, and to hold the received data set, a data set moving unit operable to read authorization information from the distribution medium, and (a) to move the data set from the distribution medium to the inside of said second receiving apparatus by removing the data set from the distribution medium, and (b) to hold the data set, only when the read authorization information shows that moving the data set is permitted, and a check-out unit operable to perform check-out when the data set is held by one of said second receiving unit and said data set moving unit, to perform the check-out based on the control information in the held data set by generating a copy of the content included in the held data set and recording the copy onto the recording medium, the copy recorded onto the recording medium being supplied to the playback apparatus, wherein said recording unit is further operable to record, into a rule management file provided in the distribution medium, the content as a plurality of contents together with corresponding usage rule information, wherein the entirety of at least one of the plurality of contents is contained in a single object file, and at least one of the plurality of contents is divided to be contained in a plurality of object files, wherein each object file has an assigned serial number that uniquely identifies the object file, wherein the rule management file contains a plurality of rule entries that are in one-to-one correspondence with the object files, wherein each rule entry has a same serial number as a serial number of a corresponding object file, wherein a rule entry that corresponds to the object file containing the entirety of the content includes corresponding usage rule information and a content identifier for the content, wherein each of a plurality of rule entries that corresponds to an object file containing a part of the at least one of the plurality of contents, which is divided, includes a content identifier for the at least one of the plurality of contents, which is divided, and one of the plurality of the rule entries includes corresponding usage rule information, wherein the distribution medium has recorded thereon pieces of track information that are in one-to-one correspondence with the object files, wherein the track information includes a time search table that shows a plurality of read addresses specifying data located in a corresponding object file at predetermined time intervals, and wherein each part of the divided content has such a length that a corresponding time search table includes at most a predetermined number of read addresses.