SuperGuide; How "At Least One of A, B, and C" Has Been Interpreted
How should the phrase “at least one of A, B, and C” be construed? Can it be understood as disjunctive, where A, B, or C can be optional? Or should it be interpreted as conjunctive, where one of each of A, B, and C are all required? Both interpretations have been used by district courts and the Court of Appeals of the Federal Circuit (“CAFC”) in the past; however, the conjunctive construction has been applied only in a particularly narrow set of fact-specific cases. Particularly, the CAFC focused on the application of grammatical principles necessitating that treatment of modifiers of a list (e.g., at least one of) be applied to all of the listed elements (e.g., A, B, and C).
In SuperGuide,[1] the CAFC affirmed a district court decision supporting DirecTV’s construction of the language “at least one of” as conjunctive. The disputed limitation in SuperGuide was “at least one of a desired program start time, a desired program end time, a desired program service, and a desired program type.” SuperGuide argued that “at least one of” refers to only one or more of the listed items, such as a desired program start time. Conversely, DirecTV argued that “at least one of” refers to one item from each of the four categories of a desired program start time, a desired program end time, a desired program service, and a desired program type. Both the CAFC and the district court agreed with DirecTV and held that “at least one of” grammatically modifies each of the four categories. The CAFC held that “an article of a preposition applying to all the members of the series must either be used only before the first term or else be repeated before each term,” citing the standard English language usage book Elements of Style(also referred to by the names of its authors “Strunk and White.” As an example of the disjunctive sense, the CAFC explained that “‘[i]n spring, summer, or winter’ means ‘in spring, in summer, or in winter.’”
One example where the conjunctive interpretation of SuperGuide was applied is Ex parte Jung,[2] where the limitation at issue was “the connection relation including at least one of a connection branch and a contents connection list.” The Patent Trail and Appeal Board (PTAB) of the United States Patent and Trademark Office construed this limitation as requiring that the connection relation includes at least one of a connection branch and at least one of a contents connection list, based on SuperGuide.
In another example, the CAFC revisited SuperGuide after nearly 20 years in the SIMO case.[3] In SIMO, the limitation at issue was “a plurality of memory, processors, programs, communication circuitry, authentication data stored on a subscribed identify module (SIM) card and/or in memory and non-local calls database.” The CAFC indicated that “the words that come immediately after the list make clear that the ‘a plurality of’ phrase applies to the individual items in the list, just as the SuperGuide canon indicates.”
Thus, the narrow construction issue decided in SuperGuide sets forth a cautionary tale in claim drafting that was not revisited by the CAFC until nearly 20 years later in SIMO. In the meantime, district courts have found a variety of meaningful ways to distinguish various claim interpretations from the construction explained by SuperGuide.
In Firtiva,[4] the district court departed from the conjunctive interpretation in SuperGuide. The Firtiva limitation at issue was “the data comprising at least one of a TV channel, content name, timestamp, time slice, and sponsor identification.” The EDTX held that the limitation should be interpreted disjunctively, as “data comprising one or more of a TV channel, a content name, a timestamp, a time slice, or a sponsor identification.” One of the reasons for this interpretation was that the data did not function as criteria for anything, but rather reflected the result of a viewer’s prior content selection. As such, the court found that it was not necessary for the data to meet all of the criteria recited in the limitation.
In Fujifilm[5] as well, a district court rejected the applicability of SuperGuide. The disputed limitation was “wherein said display includes a menu comprising selections for at least one of a transmit image mode for transmitting an image from the wireless telephone to an apparatus, a receive mail mode for receiving characters, and a transmit mail mode for transmitting characters.” The court interpreted the limitation as disjunctive. One of the reasons was that the conjunctive interpretation did not serve the purpose of the invention. According to the district court, when the limitation is read in light of the specification, it can be interpreted as at least one of a transmit image mode for transmitting an image from the wireless telephone to an apparatus, a receive mail mode for receiving characters, or a transmit mail mode for transmitting characters.
To summarize, while SuperGuide provides the conjunctive construction of the phrase “at least one of A, B, and C,” this construction has only been used in a particularly narrow set of fact-specific cases. However, for clarity, it is advisable to avoid using a modifier to a list (e.g., at least one of, a plurality of, etc.) that may be interpreted as a plural list of categories when the modifier is not intended to apply to all of the features following it. As an alternative, drafters may use “or” instead of “and” for claim drafting, for disjunctive interpretation. For instance, the above phrase can be revised as “A, B, or C” for a disjunctive interpretation.
Citation
[1] SuperGuide Corporation v. DirecTV Enterprises, Inc., 358 F.3d 870 (Fed. Cir. 2004).
[2] Ex parte Jung, Appeal No. 2016-008290 (P.T.A.B. March 22, 2017).
[3] SIMO Holdings Inc. v. Hong Kong uCloudlink Network Technology Limited, 983 F.3d 1367, 1376-80 (Fed. Cir. 2021).
[4] Firtiva Corporation v. Funimation Global Group, LLC, No. 2:21-cv-00111-JRG-RSP, 2022 WL 23165, **6-8, (E.D. Tex. Jan. 3, 2022).
[5] Fujifilm Corporation v. Motorola Mobility LLC, No. 12–cv–03587–WHO, 2015 WL 1265009, **7-9 (N.D. Cal. Mar. 19, 2015).
