A method of maintaining a status of a product item is provided. The product item includes an associated interface surface which has coded data including a plurality of coded data portions indicative of the product item's identity. The method includes, in a sensing device, sensing at least one coded data portion, generating indicating data indicative of the product item identity therefrom, and transferring the indicating data to a computer system. The computer system is responsive to the indicating data to update product status information stored in a data store. The interface surface includes at least one region having visible markings representing a respective product item status. The method including, in the sensing device, sensing coded data in the region and generating therefrom indicating data indicative of the respective product item status. The computer system is responsive to the indicating data to update the status information using the product item status.