A method and device to insure that a particular dispensing package (18) can only be engaged into an appropriate dispensing location (14). Specifically, the package and the dispenser have mating concentric rings (24, 30) (or portions thereof) to prevent engagement and dispensing of an inappropriate product. In one embodiment, the package (18) is provided with one or more concentric ring projections (24) (or portions thereof) and the dispenser (10) is provided with one or more matching concentric ring recesses (30). The projections and the recesses have similar diameters to define a mating set. In some embodiments, the concentric ring projections are placed on a closure (20), such as a cap, of the package. In alternative embodiments, the projections are placed on the dispenser and the recesses are placed on the package.