Abstract: In one aspect, the present invention features an identification tag as described herein. In a related aspect, the invention features packaging for a product that includes the identification tag and is useful in discouraging and/or detecting counterfeiting and product diversion.

Abstract: The present invention features compositions and methods useful in detecting counterfeit products and product diversion. The methods include packaging and indelibly marking products through an opening in their container and/or through a wall of the container that includes a hole therein. Unique identifiers are placed on the product and the container. In other methods, the product is not packaged within a container but is indelibly marked with first and second representations of a unique identifier, either or both of which can be machine-readable, human-readable, and/or at least partially randomized. An apparatus for carrying out the method of product marking is also disclosed.