A new report from the USPTO discusses the effectiveness of virtual patent marking.

What is virtual patent marking? From the 1920s to 2011, U.S. patent law required patent owners to mark their products with the number or numbers of associated patents. Prior to the 1920s, patent owners were required to mark their products with the the date of the patent. The main purpose of this requirement was to inform the public that the product was patented. Marking also protects the patent owner’s right to recover damages in the case of infringement.

However, marking can be costly for patent owners. Some manufacturers claim that retooling molds and reprinting labels in order to add new patent numbers or remove expired patent numbers is too expensive. Marking also may be difficult if the product is very small or protected by a large number of patents.  Companies that continue making products marked with expired patent numbers risk steep fines for false marking.

The America Invents Act of 2011 attempts to address these problems by allowing patent owners to mark their products with a website address where information about associated patents is listed.

One of the long-term problems with virtual marking is that it could make it much more difficult to track down patents associated with a specific product that is no longer produced or from a company that no longer exists. For example, antique collectors often use patent numbers to identify and authenticate old tools, toys, utensils, machinery, etc.