U.S. patent law[]
The best mode requirement of 35 U.S.C. §112 adds a subjective test: if the inventor has developed techniques that he or she recognizes at the time of filing as the best way of carrying out the invention, those techniques must be disclosed.
The purpose of the "best mode" requirement is to prevent inventors from applying for patents while concealing from the public the preferred embodiment or implementation of the invention.[1]
Computer software[]
The meaning of this requirement in the context of computer software has been explored by the courts. The claims in In re Sherwood[2] were rejected by the examiner for failure to disclose any computer hardware, flow charts, algorithms, or programs with which best mode would operate. Yet the court overturned that determination, asserting that the question is not how an applicant discloses the best mode, but whether he has done so. The Court of Customs and Patent Appeals (C.C.P.A.) concurred, stating:
| “ | [T]here is no objective standard by which to judge the adequacy of a best mode disclosure. Instead, only evidence of concealment (accidental or intentional) is to be considered. That evidence, in order to result in affirmance of a best mode rejection, must tend to show that the quality of an applicant’s best mode is so poor as to effectively result in concealment.[3] | ” |
Notwithstanding the applicant’s failure to disclose the listing of the known program, the disclosure was sufficient to satisfy the best mode requirement.
In White Consolidated Industries, Inc. v. Vega Servo-Control, Inc.,[4] a program that was an essential element to a claim for machine tool had been identified in the patent specification as an example. The program was not disclosed in the specification, but rather was maintained as a proprietary trade secret. The court held that, absent disclosure of the program, the specification required a great deal of experimentation by a skilled programmer to develop a workable program to make the invention operational. The proprietary nature of the program was irrelevant, given that it was the only way of disclosing the best mode of practicing the invention. The U.S. Court of Appeals for the Federal Circuit invalidated the patent on the ground that the disclosure failed to satisfy the enablement requirement under 35 U.S.C. §112.