Many of the formality requirements for a patent are found in a single U.S. statute, 35 U.S.C. 112, which states, in part,
(a) In General. The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention.
(b) Conclusion. The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
(c) Form. A claim may be written in independent or, if the nature of the case admits, in dependent or multiple dependent form.
There are multiple requirements embedded in this language, including enablement, written description, definiteness, and best mode. The Federal Circuit’s recent decision in Gramm v. Deere & Co. addresses the definiteness requirement. The determination of definiteness requires a person working in the field must be capable of understanding the scope of meaning of a claim,[i] while considering the specification and prosecution history.[ii] This is typically satisfied, as claims are found indefinite only if the claims do not provide reasonably certainly to a person working in the field as to the claim scope”[iii] This is more than having difficult claim construction, rather is “insolubly ambiguous”.[iv]
Markush claims[v] are largely examined similarly to other claims. However, the inclusion of a large number of options in Markush claims does not impact definiteness unless a person working in the field would be unable to discern the scope, i.e. unable to envision the members of the group.[vi]
In the case of means-plus-function claim language,[vii] the law permits a claim to provide for a structural element by claiming through the function provided instead of structure.[viii] However, while the use of “means” in the claims will start a means-plus-function analysis, inclusion of structural elements in the claim removes the limitation from a means-plus-function analysis.[ix] Where the claim language meets the means-plus-function requirements, the function(s) performed by the means must first be identified, followed by determining any structure in the specification that corresponds to the function.[x] The analysis should be only what is necessary to perform the claimed function, but that systems discussed in the specification that added function should not be ignored.[xi] Further, where the claimed device relies on a computer or microprocessors, prior caselaw stated that the structure of a microprocessor, for means-plus-function, is limited to the algorithm,[xii] as general purpose microprocessors are considered programmed in variously different ways and the specific programming converts the general purpose processor into a special purpose machine for a specific function.[xiii] If the claimed structure is not a microprocessor or computer, such as where circuitry is used to achieve the functions, the algorithm requirement is not implicated.[xiv] However, any versions that require a microprocessor require an algorithm, even if other variants do not require a microprocessor and therefore do not need an algorithm.[xv]
The consequences of an allegation of indefiniteness can have stark consequences, including invalidation of a patent.[xvi]
[i] Power-One, Inc. v. Artesyn Techs., Inc., 599 F.3d 1343, 1350, 94 U.S.P.Q.2d 1241, 1245 (Fed. Cir. 2010) (citing Haliburton Energy Svcs., Inc. v. M-1 LLC, 514 F.3d 1244, 1249-51 (Fed. Cir. 2008)).
[ii] Pressure Products Medical Supplies, Inc. v. Greatbatch Ltd., 599 F.3d 1308, 1314-1315 (Fed. Cir. 2010).
Power-One, Inc., 599 F.3d at 1350.
[iii] Nautilus, Inc. v. Biosig Instruments, Inc., 572 U.S. 898, 911 (2014).
[iv] Power-One, Inc., 599 F.3d at 1350 (citing Exxon Research Eng’g Co. v. United States, 265 F.3d 1371, 1375 (Fed. Cir. 2001); Datamize LLC v. Plumtree Software, Inc., 417 F.3d 1342, 1347 (Fed. Cir. 2005)).
[v] Markush claim language is a list of alternatively useable species. … the phrase “Markush claim” means any claim that recites a list of alternatively useable species regardless of format, such as the general formula A, B, C, or D.
[vi] See, MPEP 2173.05(h).
[vii] Claim language that includes means or similar language with functional results from the means:
“control means … for raising or lowering the header in accordance with said first signal in maintaining the header a designated height above the soil” Gramm v. Deere & Co., Case No. 2024-1598 at 3 (Mar. 11, 2026).
[viii] Gramm v. Deere & Co., Case No. 2024-1598 at 7 (Mar. 11, 2026).
[ix] Phillips v. AWH Corp., 415 F.3d 1303, 1311, 75 U.S.P.Q.2d 1321 (Fed. Cir. 2005).
[x] Gramm at 8 (citing Williamson v. Citrix Online, LLC, 792 F.3d 1339, 1351 (Fed. Cir. 2015)).
[xi] Id. at 10.
[xii] Id. at 8 (citing WMS Gaming, Inc. v. Int’l Game Technol., 184 F.3d 1339, 1348 (Fed. Cir. 1999).
[xiii] Id. (citing Aristocrat Techs. Austl. Pty Ltd. V. Int’l Game Tech.., 521 F.3d 1328, 1333 (Fed. Cir. 2008)).
[xiv] Id. at 12.
[xv] Id. at 14 (See, Typhoon Touch Techs., Inc. v. Dell, Inc., 659 F.3d 1376, 1386 (Fed. Cir. 2011).
[xvi] Nautilus, Inc., 572 U.S. at 911.
