to retransmit on a full-time basis all signals which it is authorized to carry, the values for independent, network, and noncommercial educational stations set forth above, as the case may be, shall be multiplied by a fraction which is equal to the ratio of the broadcast hours of such station carried by the cable system to the total broadcast hours of the station. A "network station" is a television broadcast station that is owned or operated by, or affiliated with, one or more of the television networks in the United States providing nationwide transmissions, and that transmits a substantial part of the programing supplied by such networks for a substantial part of that station's typical broadcast day. An "independent station" is a commercial television broadcast station other than a network station. A "noncommercial educational system" is a television station that is a noncommercial educational broadcast station as defined in section 397 of title 47. Section 112. Limitations on exclusive rights: Ephemeral recordings. (a) Notwithstanding the provisions of section 106, and except in the case of a motion picture or other audiovisual work, it is not an infringement of copyright for a transmitting organization entitled to transmit to the public a performance or display of a work, under a license or transfer of the copyright or under the limitations on exclusive rights in sound recordings specified by section 114(a), to make no more than one copy or phonorecord of a particular transmission program embodying the performance or display, if-- (1) the copy or phonorecord is retained and used solely by the transmitting organization that made it, and no further copies or phonorecords are reproduced from it; and (2) the copy or phonorecord is used solely for the transmitting organization's own transmissions within its local service area, or for purposes of archival preservation or security; and (3) unless preserved exclusively for archival purposes, the copy or phonorecord is destroyed within six months from the date the transmission program was first transmitted to the public. (b) Notwithstanding the provisions of section 106, it is not an infringement of copyright for a governmental body or other nonprofit organization entitled to transmit a performance or display of a work, under section 110(2) or under the limitations on exclusive rights in sound recordings specified by section 114(a), to make no more than thirty copies or phonorecords of a particular transmission program embodying the performance or display, if-- (1) no further copies or phonorecords are reproduced from the copies or phonorecords made under this clause; and (2) except for one copy or phonorecord that may be preserved exclusively for archival purposes, the copies or phonorecords are destroyed within seven years from the date the transmission program was first transmitted to the public.