"For Use Under" Patent Marking: When A Claim Only Partially Covers The Product

• Published date: 01 December 2022
• Subject Matter: Intellectual Property, Patent
• Law Firm: Holland & Knight
• Author: Mr Jacob W Schneider

The Patent Act requires patentees to mark their products with the numbers of any patents that cover that product. Put differently, if you produce a product that would infringe one of your patents, you must mark that product with the patent number. But what should a patent owner do if their product covers only a portion of a patented claim? Because software often covers only a portion of a patented claim, this article examines the patent marking requirement in that context and recommends best practices.

The Patent Marking Requirement

The Patent Act requires that patentees put the world on notice that their products are covered by a given patent:

Patentees, and persons making, offering for sale, or selling within the United States any patented article for or under them, or importing any patented article into the United States, may give notice to the public that the same is patented, either by fixing thereon the word "patent" or the abbreviation "pat.", together with the number of the patent . . .

35 U.S.C. ' 287(a). Although this is written with permissive language ("may give notice"), the penalty for not marking is a strict limitation on later damages:

In the event of failure so to mark, no damages shall be recovered by the patentee in any action for infringement, except on proof that the infringer was notified of the infringement and continued to infringe thereafter, in which event damages may be recovered only for infringement occurring after such notice.

35 U.S.C. ' 287(a). In other words, if you fail to mark your product, then you cannot accrue damages until the moment the defendant became aware of the infringement (typically by written notice or filing a complaint). As a result, nearly every product bears a patent marking of some kind that either lists the numbers of patents that cover the product or provides a link to a website that does the same.

This marking requirement advances of the Patent Act: "to promote the progress of science and useful arts[.]" Constitution, Art. I ' 8. Specifically, because every patent must "contain a written description of the invention, and of the manner and process of making and using it[,]" someone curious about how a product works can examine its marked patents. 35 U.S.C. ' 112. The marking requirement also puts the public on notice that copying the product risks a patent infringement claim.

The Patent Act also prohibits marking a product when it is not warranted. Such "false marking" could lead to criminal or...