A plasma display panel having an excellent image display quality and high reliability is provided by preventing deterioration of a phosphor due to hydrocarbon gas remaining in the plasma display panel. Ships utilizing the marine ship tracking system periodically transmit reports to a remote tracking center. Furthermore, an associated method of forming calendered sheets of material formed of the composition is disclosed. Another subset of the plurality of keys corresponds to a number of temporary re-recordable audio inputs that are provided by the user.