A computer that generates a product tag for a product is described. During operation, the computer may obtain information specifying multiple document locations associated with the product based at least in part on different environmental conditions of the product. Then, the computer may generate the product tag (or additional information specifying the product tag), where the product tag includes location information specifying the document locations. Moreover, given location information is associated with a given functional ink or is associated with a given state of a circuit in the product tag that is responsive to a given environmental condition. Furthermore, the environmental conditions for different functional inks or different states of the circuit are different, such that, at a given time, the product tag presents location information for a given one of the document locations. Next, the computer may provide the additional information specifying the product tag to the electronic device.