Media and method of updating commodity catalog information

A method of purchasing from and updating commodity catalog information recorded on a medium, comprising:

• accessing a server corresponding to existing commodity catalog information read from the medium, after user registration;
• receiving updated commodity catalog information from the server;
• and
• writing the received updated commodity catalog information on a writeable area of the medium,
• wherein:
• the existing commodity catalog information is written in a read-only area of the medium, and
• the updated commodity catalog information is written in a write once area of the medium.

A method of purchasing from and updating commodity catalog information recorded on a medium, comprising:

• accessing a server corresponding to existing commodity catalog information read from the medium, after user registration;
• receiving updated commodity catalog information from the server;
• writing the received updated commodity catalog information on a writeable area of the medium;
• and
• displaying both the existing and updated commodity catalog information such that the updated commodity catalog information is marked to be distinguishable from the existing commodity catalog information,
• wherein:
• the existing commodity catalog information is written in a read-only area of the medium,
• the existing commodity catalog information has a corresponding age that is read from the medium,
• the updated commodity catalog information has a corresponding age that is read from the server, and
• said receiving the updated commodity catalog information comprises
• comparing the ages of the existing and updated commodity catalog information, and
• receiving the updated commodity catalog information where the ages are different.

A recording/reproducing medium, comprising:

• a read-only area in which original commodity catalog information is written;
• and
• a writeabte area in which updated commodity catalog information is written when provided by a server, after user registration,
• wherein said writeable area comprises:
• a write once area to which data can be written once;
• and
• a rewriteable area to which data can be repeatedly written and/or from which data can be erased.