A data read/write apparatus records, in a root directory of a recording
medium, a file "MEM*****.ind" indicating the type of the recording medium,
a directory "DCIM" for storing still image files, a directory "VOICE" for
storing voice files, a directory "HIFI" for storing audio files, and a
directory "MS******" for storing information inherent to a vendor. The
rules are defined as the method for recording data in the recording
medium. Hence, an audio-visual apparatus can determine the type of data
stored in the loaded recording medium, recognizes the format of data in a
non-conforming format, and erases the data in the non-conforming format.
