An electronic device intended for use as a tag to be attached to identify contents of the container to which it is attached. In particular, the present invention relates to an electronic tag which has a facility for storing delivery information and is equipped with a responding means for transmitting the delivery information stored therein in response to a query signal received from an interrogating apparatus. Codes, including items such as the names and addresses of the destination and the sender, and a sorting code are written into predetermined blanks of a delivery label, and into a memory. The memory responds to a query by transmitting the sorting information to allow automated sorting. The tag may be initiated only when torn, to extend battery shelf life.