Patent owners that practice their invention are at a disadvantage compared to nonproducing patentees. The patent marking statute, 35 U.S.C. § 287(a), says that patentees that make and sell patented products or authorize others to do so, may mark their patented products and put the public on notice that the product is patented. However, failure to mark a patented product made or offered for sale limits the infringement damages available to the patent owner. In the absence of patent marking, damages are recoverable only for infringement that occurs after the infringer received notice of the infringement. Thus, for patent owners that make and sell a patented product without marking it, the patent marking statute operates as a forfeiture of damages, which may be substantial depending on the duration of infringement prior to providing the infringer with notice. There is no corresponding risk of forfeiture for nonproducing patentees.
From a practical standpoint, one of the challenges many patent owners face is the manufacturing cost of changing tooling and dies when a patent issues for a product that it may have been making and selling for years. This challenge is further complicated by the fact that a product, or components or subsystems of the product, may be covered by multiple patents, each with a different expiration date. From a legal standpoint, it may not be possible to know which patent or patents are likely to be most important from an enforcement perspective and which are most critical to be included in the patent marking strategy.