Cite as: 535 U. S. 722 (2002)
Syllabus
(a) To enable a patent holder to know what he owns, and the public to know what he does not, the inventor must describe his work in "full, clear, concise, and exact terms." § 112. However, patent claim language may not describe with complete precision the range of an invention's novelty. If patents were always interpreted by their literal terms, their value would be greatly diminished. Insubstantial substitutes for certain elements could defeat the patent, and its value to inventors could be destroyed by simple acts of copying. Thus, a patent's scope is not limited to its literal terms, but embraces all equivalents to the claims described. See Winans v. Denmead, 15 How. 330, 347. Nevertheless, because it may be difficult to determine what is, or is not, an equivalent, competitors may be deterred from engaging in legitimate manufactures outside the patent's limits, or lulled into developing competing products that the patent secures, thereby prompting wasteful litigation. Each time the Court has considered the doctrine of equivalents, it has acknowledged this uncertainty as the price of ensuring the appropriate incentives for innovation, and it has affirmed the doctrine over dissents that urged a more certain rule. See, e. g., id., at 343, 347. Most recently, Warner-Jenkinson, supra, at 28, reaffirmed the doctrine. Pp. 730-733.
(b) Prosecution history estoppel requires that patent claims be interpreted in light of the proceedings before the Patent and Trademark Office (PTO). When the patentee originally claimed the subject matter alleged to infringe but then narrowed the claim in response to a rejection, he may not argue that the surrendered territory comprised an unforeseen equivalent. See Exhibit Supply Co. v. Ace Patents Corp., 315 U. S. 126, 136-137. The rejection indicates that the patent examiner does not believe the original claim could be patented. While the patentee has the right to appeal, his decision to forgo an appeal and submit an amended claim is taken as a concession that the invention as patented does not reach as far as the original claim. See, e. g., Goodyear Dental Vulcanite Co. v. Davis, 102 U. S. 222, 228. Were it otherwise, the inventor might avoid the PTO's gatekeeping role and seek to recapture in an infringement action the very subject matter surrendered as a condition of receiving the patent. Pp. 733-735.
(c) Prosecution history estoppel is not limited to amendments intended to narrow the patented invention's subject matter, e. g., to avoid prior art, but may apply to a narrowing amendment made to satisfy any Patent Act requirement, including § 112's requirements concerning the patent application's form. In Warner-Jenkinson, the Court made clear that estoppel applies to amendments made for a "substantial reason related to patentability," 520 U. S., at 33, but did not purport to catalog every reason that might raise an estoppel. Indeed, it stated that even
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