The data structure includes a navigation area of a computer readable
medium storing navigation data associated with a data stream representing
a portion of at least one reproduction path. The navigation data includes
indication information, and the indication information indicates whether
the data stream represents multiple reproduction paths or the data stream
represents a single reproduction path. If the indication information
indicates the data stream represents multiple reproduction paths, the
navigation data includes path number information and an indicator
associated with each reproduction path. The path number information
identifies a number of the multiple reproduction paths, and each
indicator indicates a file associated with the associated one of the
multiple reproduction paths.