Examples of Linguistic (In)definiteness

After reading his recent law review note on indefiniteness, I asked Michigan Law student Gary Fox to apply his framework to the new Federal Circuit decision of Capital Security Systems, Inc. v. NCR Corp. – DC

Guest Post by Gary M. Fox (garymfox@umich.edu), University of Michigan Law School

In Nautilus, Inc. v. Biosig Instruments, Inc., the Supreme Court articulated the standard for indefiniteness under 35 U.S.C. § 112: “[A] patent is invalid for indefiniteness if its claims, read in light of the specification delineating the patent, and the prosecution history, fail to inform, with reasonable certainty, those skilled in the art about the scope of the invention.”[1] Since then, courts have had nearly four years to apply this new standard.

I have previously argued that the reasonable-certainty standard might be understood as imposing two separate requirements: linguistic and physical definiteness.[2] Under my proposed framework, a claim is linguistically indefinite if it is open to multiple constructions but one construction is not clearly correct. Additionally, a claim is physically indefinite if it uses a comparative term or involves an ambiguous spatial relationship but is not limited to a narrow range. In this view, a claim that is either linguistically or physically indefinite fails to meet Nautilus’s reasonable-certainty standard.

Last week, the Federal Circuit handed down a nonprecedential decision in Capital Security Systems, Inc. v. NCR Corp.[3] In that case, the court considered whether two different claim terms were definite.

Capital Security holds four patents that are directed to an automated document cashing machine.[4] Three of those patents are continuation patents that share the parent patent’s specification and priority date.

The independent claims in the continuation patents contain the phrase “ascertains an apparent signature” or a highly similar variation.[5] For example, a representative claim includes the following limitation: “the processor reviews images from a legal amount recognition (LAR) line and a courtesy amount recognition (CAR) line and ascertains an apparent signature from the document image in order to validate the document.”[6]

The other term at issue was “transactional operator.” One claim in the parent patent includes the following language: “a transactional operator for operation by the user to perform a transaction upon deposit of sufficient cash by user for the requested transaction.”[7] The parent patent’s specification does not use the term “transactional operator,” but it does describe a microcomputer, keyboard, and display.

On NCR’s motion for summary judgment, the district court held that “ascertains an apparent signature” and “transactional operator” were both indefinite.[8] The court credited NCR’s expert, who offered four possible meanings for “apparent signature.”[9] NCR’s expert also offered three possible meanings for “transactional operator.”[10] In both cases, he testified that a skilled artisan would not have been able to decide amongst the possible options. The district court agreed and found the claims invalid.

In its decision on appeal, the Federal Circuit reversed the district court’s holding that “ascertains an apparent signature” was indefinite. The court reasoned that “a skilled artisan would understand the claimed ascertaining step to correspond to determining the presence of a signature on the signature line of a check.”[11] It found that the claim had been written to encompass all four of the options that NCR’s expert presented. The court rejected NCR’s argument that the term was indefinite because it was not tied to an “objective standard of measure.”[12] It also pointed out that Capital Security had not “muddle[d] the scope” of the term during prosecution.[13]

On the other hand, the Federal Circuit affirmed the district court’s holding that “transactional operator” was indefinite. The court noted that it was unclear whether that term included the microcomputer, the keyboard, and the display, or only a subset of those components.[14] During oral argument, counsel for Capital Security contended that the microcomputer and keyboard counted as the “transactional operator” but that the display did not count. Because “transactional operator” did not have a “commonly-accepted definition,” the court found the term indefinite.[15]

For both “ascertains an apparent signature” and “transactional operator,” NCR presented arguments grounded in linguistic indefiniteness. For each term, it asserted that there were multiple possible constructions but that no construction was clearly correct. That strategy makes sense. After all, the Federal Circuit had previously held claim terms with three or four possible meanings indefinite.[16]

For “ascertains an apparent signature,” the court essentially found that NCR’s expert presented a false choice among four constructions when the claim was drafted to encompass all four options. With one slightly broader construction that was clearly correct, any potential linguistic indefiniteness problem disappeared.

But for “transactional operator,” there was a legitimate linguistic indefiniteness problem. The court could not identify which components counted. For example, the “transactional operator” could have been the microcomputer and keyboard; the microcomputer and display; the keyboard and display; or the microcomputer, display, and keyboard. Even if some of these combinations were likelier than others, a skilled artisan would not have known which construction was correct. Therefore, the term suffered from linguistic definiteness.

As I have said before, my proposed framework of linguistic and physical definiteness might not work for every conceivable case.[17] But it seems to work for Capital Security Systems v. NCR, and it may be a helpful starting point for understanding the reasonable-certainty standard in the wake of Nautilus.

= = = = =

[1] 134 S. Ct. 2120, 2124 (2014).

[2] Gary M. Fox, Note, Understanding Nautilus’s Reasonable-Certainty Standard: Requirements for Linguistic and Physical Definiteness of Patent Claims, 116 Mich. L. Rev. 329 (2017).

[3] Capital Security II, No. 2017-2368, 2018 WL 1181197 (Fed. Cir. Mar. 7, 2018).

[4] U.S. Patent No. 5,897,625; U.S. Patent No. 7,653,600; U.S. Patent No. 7,991,696; U.S. Patent No. 8,121,948.

[5] Capital Security II, 2018 WL 1181197, at *1.

[6] Id. at *2 (emphasis added by court) (quoting U.S. Patent No. 7,653,600 col. 39 l. 35 – col. 40 l. 11).

[7] Id. (emphasis added by court) (quoting U.S. Patent No. 5,897,625 col. 24 ll. 31–53).

[8] Id. at *3 (citing Capital Sec. Sys., Inc. v. NCR Corp. (Capital Security I), 263 F. Supp. 3d 1366, 1375 (N.D. Ga. 2017)).

[9] According to NCR’s expert, the four possible meanings were as follows: “(1) determining if anything in the way of a mark was present in the signature field, useful or otherwise; (2) distinguishing a mark resembling legible text from a mark never intended to be a signature, such as a scratch or smudge mark; (3) determining if the scanned image field corresponds to a handwritten cursive signature versus an otherwise legitimate block letter printed name; or (4) determining if the signature is forged.” Id. (quoting Capital Security I, 263 F. Supp. 3d at 1373).

[10] Again, according to NCR’s expert, the options for this term were “(1) a user interface allowing user selections; (2) an internal computer component like software executing an algorithm; or (3) a computer component that performs” a certain task. Id. at *4.

[11] Id.

[12] Id. at *5.

[13] Id.

[14] Id. at *5.

[15] Id. at *6.

[16] Fox, supra note 2, at 344–45, 345 n.118 (first citing Teva Pharms. USA, Inc. v. Sandoz, Inc., 789 F.3d 1335 (Fed. Cir. 2015); then citing Dow Chem. Co. v. Nova Chems. Corp. (Can.), 803 F.3d 620 (Fed. Cir. 2015)).

[17] Id. at 348.

29 thoughts on “Examples of Linguistic (In)definiteness

  1. 4

    Many people want patent claims to be as precise as geometry theorems. It isn’t and never will be. There are always shades of gray no matter how much you may not like it or want to draft up some “rule” to determine if something is indefinite or not.

    We are dealing with the English language and (good) patent prosecutors draft claims as vague/broad as possible and litigators stretch the claims as best they can to avoid prior art and cover asserted infringement.

    You may not like it, you may detest it, but that is the framework.

    Replacing the SC standard for indefiniteness with a substitute “rule” doesn’t advance anything when the substitute rule needs a handful of exceptions and when applied to cases doesn’t yield the same results as accepted opinions…

  2. 3

    Isn’t the most common of the relatively few Fed. Cir. sustained “indefiniteness” decisions now for the situations of “means-function” claim terms with no such “means” in the specification?

    1. 3.1

      By the way, isn’t what a cashier does in deciding whether to cash your check is to look at the amount, the signature, and the amount in your account?

      1. 3.1.1

        As usual, such a comment merits the response of:

        link to xkcd.com

        Those who understand patent law will understand why this panel presents a timeless distinction important to the point provided by Paul.

      2. 3.1.2

        Translating spoken word to printed text is what secretaries used to do too. That doesn’t mean getting a computer to do it is not an invention, even in combination with Gary Seven’s typewriter.

        link to youtube.com

        Hey… do you think there is a link between Gary Seven and Seven of Nine?


          Translating spoken word to printed text is what secretaries used to do too. That doesn’t mean getting a computer to do it is not an invention

          But it definitely means that the concept of “computer does it” is not an invention.

          And that’s all we have here.


            This is one of those times where I absolutely agree with you.

            I see this occasionally as an examiner. Applicant argues that the prior art recognized that it was hard or impossible to do X, and now they are claiming “doing X.” Great, I respond. HOW do you do X? Usually they “do X” the same way the prior art did whatever it did that wasn’t X, but magically it achieves X. Guess what? No patent for you!


              I agree with you exert, but not with Malcolm (or your carry-through to Malcolm).

              The difference is in the Means to the End of “no patent for you.”

              Malcolm would have this be a matter of patent eligibility – as opposed to it being a matter of patentability (the legal requirements of 102/103/112).


                I’m struggling to fully parse your comment (could just be me, long night).

                I see this as a 112 issue, enablement, NOT a 101 issue. In fact, I see MOST 101 issues as actually 112, 102, or 103 issues.

                1. Those are things I picked up from your response, exert (and to which, reasonable people may progress along a dialogue).

                  However, those are also items that Malcolm will not support.

                  In other words, YOU are correct in so far as the substantive items you indicate, but you are completely incorrect in agreeing with Malcolm as to any such point, because THAT is not what Malcolm is about.

                  Your attribution to Malcolm is in error.


            Really, that’s all we have here? Then my hats off to the guy or gal that stretched “computer does it” into a 95 page published patent including 36 figures and 11 columns of code.


              95 published pages, 36 figures, and 11 columns of code and yet no structure for a key claim term… You should probably put your hat back on (seriously, its easy to write a lot of pages about nothing. Its much harder to write a few pages with meaning).



                Are you aiming to make something of which is optional to somehow be not optional?

                (just curious, as I really do not know exactly what the “key claim term” means to you)


                Which key claim term is that? My impression is that it is only key in the sense that the infringers found something to complain about.

    2. 3.2

      Good point! I acknowledge in my Note (335 n.50) that there’s a different standard for M+F claims. My framework focuses only on claims that don’t include functional language.

      1. 3.2.1

        Worth noting Gary – the exacting distinction that the optional claim format provided by 35 USC 112(f) provides, noting that quite apart from this option, combination claims with some terms using language sounding in function have been – and have been since the Act of 1952 – fully permissible (read that as not invoking indefiniteness) when the claim as a whole is understood.

        Sadly, there are plenty of those who would seek to use the provided option of FULLY functional claiming as some extra-legal constraint on claim forms (and thereby ignoring what Prof. Crouch has coined as the Vast Midle Ground).

        Some will even atop of that attempted obfuscation, attempt to insert some type of “Point of Novelty” in a 101 sense into the discussions.


          combination claims with some terms using language sounding in function have been – and have been since the Act of 1952 – fully permissible

          “Fully permissible”?


  3. 2

    if it uses a comparative term or involves an ambiguous spatial relationship but is not limited to a narrow range.

    This statement itself would fail the proposed rule.

    What is the meaning of the word “narrow” as it is used in the rule?

    (turtles all the way down)

    1. 2.1

      Thanks for your thoughts. I agree that the meaning of “narrow” is flexible, but my goal was to find a standard that is (1) fits the vast majority of the cases and (2) is more specific than “reasonable certainty.” For the best examples of physical definiteness, check out my discussion of Warsaw Orthopedic and Nautilus itself on pp. 346–47 in my Note. In both of those cases, it’s interesting to see that narrowness is tied to a length dictated by the human body.

      1. 2.1.1

        The problem with your attempt Gary is as I noted: your own rules fail the rules that you set out.

        Whether or not “vast majority” may attach pails in comparison to the recursive error inherent in your foundation.

        Sure, one may – in a case by case situation – seek to ADD items that further constrain just what “narrowness” may mean, but that does not help your (free-standing) and overall approach.

        All that you have done is “hand wave” the issue on a first pass – an issue that remains a core issue.

        In essence, you still employ a type of “I know it when I see it.”


          This reminds me of claim construction where a party attempts to substitute an even more confusing construction for a term that is understood by a person of ordinary skill but disfavored by the party pushing for something else.

  4. 1

    What distinguishes between a recitation whose scope includes multiple meanings which are then identified as multiple “possible constructions” and a recitation whose scope includes the same multiple meanings but which is identified merely as broadly covering all the example possibilities?

    When IS it valid to assume a requirement of “choosing” between the multiple referents of a recitation arises?

    The clarity of a recitation is a property of a relationship between the words recited and the concretes which are its referents. How could any recitation be linguistically definite but physically indefinite or linguistically indefinite but physically definite?

    Recitation: “A, B, and C, collectively comprise a D”

    Is the relationship between the words and the referents clear?

    1. 1.2

      Thanks for your excellent (and tough!) questions. When deciding whether a claim is definite, courts don’t need to rely solely on the claim language–they can look at all of the intrinsic evidence. In Capital Security, my impression is that the disclosures in the specification allowed for a broad scope rather than multiple possible constructions. I think it will be interesting to see how this reasoning develops as more litigants adopt similar strategies and present arguments based on multiple possible constructions.

      I agree that there might be situations where linguistic and physical definiteness overlap. As for “A, B, and C, collectively comprise a D”: If the state of the art is such that there are really only a few possible options to connect A, B, and C, then it looks like a linguistic definiteness problem. But if the relationship between the claim elements is even more vague, then it looks like a physical definiteness problem. You could imagine a space in the middle where you might characterize the imprecision as either problem, but I don’t think it’s necessary to be able to draw a sharp line between the two.

      1. 1.2.1

        my impression is that the disclosures in the specification allowed for a broad scope

        I am not certain just how much “hands-on” experience you have with patent prosecution, Gary, but most all applications are written with “weasel words” (an admittedly self-denigrating way of describing what is in essence merely good lawyering) that provide for “breadth of scope is not indefiniteness” take-aways.

        An ongoing “dialogue” on these pages involves different schools of thought as to how claim writing has evolved over time. One telling metric in this conversation is the frequency of the use of the optional claim format known as the Jepson claim. Virtually an extinct dinosaur, the Jepson claim format simply does not provide sufficient value to the end client as compared to other claim formats.

        There are those attorneys (typically seeking to re-install old philosophies), that would have it that the law as written by Congress (through the guise of “indefiniteness”) requires the Jepson claim format.

        As any rational view would show, this view simply cannot stand.

        We are then left with the plain and unassailable fact that “ladders of abstraction” and pretty much nearly ALL claims that provide any meaningful value to clients, engage in claim forms (that in addition to NOT being painstakingly detailed “picture claims”) that eliminate the “choice” of litigants attacking patent claims based on your “linguistic definiteness” approach.

        Your approach is fundamentally flawed, and that fundamental flaw stems from the nature of language itself.

        There is to be NO “ You could imagine a space in the middle where you might characterize the imprecision as either problem, but I don’t think it’s necessary to be able to draw a sharp line between the two” because your “theory” itself crashes (as mentioned elsewhere, your rules fail the very rules you set out).

      2. 1.2.2

        Thank you for your reply.

        I’m interested in the concrete example because it may be more illustrative of your position.

        Why would “A, B, and C, collectively comprise D” be linguistically indefinite even if “in reality there are only a few possible options”?

        If, in reality, only A and B combine to form D, then in a case of a particular A, B, and C, where A and B did comprise D, would not A, B, and C collectively comprise D?

        The recitation imposes no limits on HOW the collective A, B, and C comprises D. The only limitation is THAT they collectively comprise D.

        The “test” for the claim is, “is it true THAT A, B, and C, collectively comprise D”? Is such a question of infringement or no, unanswerable in any specific case, or in the abstract?

        Where the indefiniteness?

Comments are closed.