Patent ID: 7721961

Claim:
A method of maintaining a status of a product item, the product item including an associated interface surface, the interface surface having disposed thereon or therein coded data including a plurality of coded data portions, each coded data portion being indicative of an identity of the product item, the method including, in a sensing device: sensing at least one coded data portion; generating, using the sensed coded data portion, indicating data indicative of the product item identity; and transferring the indicating data to a computer system, the computer system being responsive to the indicating data to update product status information stored in a data store, wherein each coded data portion is indicative of the respective position, and wherein the method includes, generating in the sensing device and using the sensed coded data portion, indicating data indicative of at least one of a position of the sensed coded data portion on the interface surface and a position of the sensing device relative to the interface surface.