‘Best mode’ is the requirement that a patent applicant disclose the best way that the applicant knows to practice an invention.  The purpose of the ‘best mode’ requirement is to fulfill the public disclosure goals of the patent system by preventing a patent applicant from obtaining a patent while at the same time keeping the best parts of the invention secret.

The ‘best mode’ requirement is present both under the America Invents Act, signed into law on September 16, 2011, and under prior law.  Section 15 of the Act changed the law so that failure by the patent applicant to disclose ‘best mode’ is no longer a reason to declare a patent invalid or unenforceable.  This provision is effective immediately and removes ‘best mode’ as an issue in infringement and invalidity litigation.  The change will make litigation a little shorter and a little less expensive.

Is the best mode requirement now completely toothless?  Not quite, according to someone who took part in the discussions at the time.  ‘Best mode’ is still a requirement of Federal law and failure to disclose best mode potentially subjects the applicant to criminal penalties and patent attorneys to disbarment, just like it did before the Act.  Do we expect Federal prosecutors to drop their cases against bank robbers, terrorists and counterfeiters to pursue less-than-completely-forthcoming inventors?  Not likely.

Why is this change important for patent applicants?  The chances of being called out on a ‘best mode’ question just went from pretty good to very low.  While we would never advise a client to provide anything other than ‘best mode’ (it’s a requirement of Federal law, after all), the applicant may wish to be more aggressive in determining what is or is not ‘best mode’ and hence must be disclosed in a patent application.

— Robert Yarbrough, Esq.