Patent practitioners are well-acquainted with the Broadest Reasonable Interpretation (BRI) standard. While much has been written in how to scrutinize the examiners’ application of BRI to claim terms, there are other forms of interpretive broadness that can escape critical focus. Namely, what about the breadth with which an examiner interprets the teachings of the prior art? This is a distinct, yet equally impactful, issue that arises frequently during obviousness rejections, especially when an examiner stretches beyond what a reference fairly teaches in search of a rationale for combination. This posts explores these issues in the context of a recent PTAB decision related to frozen egg patties.
The BRI standard governs how claim language is construed during patent examination. And along the lines of BRI, when it comes to prior art references, the examiner’s mandate is to evaluate what the prior art teaches through the lens of a person having ordinary skill in the art (PHOSITA), while also considering the reference in its entirety.
This post addresses the particular situation when an examiner is interpreting the disclosure of a prior art reference that uses a permissive or open-ended phrase (e.g., “not particularly limited”). Such phraseology is common in patent applications where an applicant is disclosing the invention with a particular example or embodiment, but does not want the invention limited only to that example or embodiment.
A recent decision from the Patent Trial and Appeal Board (PTAB) illustrates an example. In Appeal No. 2024-002020, involving Application 17/514,044, the Board reversed an obviousness rejection that relied on an examiner’s overly broad reading of a prior art reference concerning a frozen egg patty invention.
Claim 1 on appeal is provided below:
A frozen food product comprising:
egg having a total weight;
an additive comprising calcium and being combined with the egg, wherein a total weight of the additive is 0.02% to 0.15% of the total weight of the egg such that a first microwave heating time is required to achieve a target temperature of the egg; and
a bread component, wherein the first microwave heating time is less than a second microwave heating time that would be required to achieve the target temperature of the egg if the egg did not include the additive, and wherein the bread component would be unpalatable when subject to the second microwave heating time.
Missing from the prior art was the calcium additive. The Examiner cited a secondary reference as teaching the use of a calcium-containing agent to improve texture, asserting that this agent could be applied to any food, including frozen egg patties. This assertion was based on a statement in the reference that “[t]he type of food to which the texture modifier of the present invention can be applied is not particularly limited, but it can be effectively used for foods containing wheat flour as a main ingredient.” From this, the Examiner concluded that the agent could be applied to any food product, including the egg patty of the claimed invention, even though the egg product is not a baked good and contains no wheat flour.
The PTAB disagreed, finding this interpretation too broad:
… A person having ordinary skill in art would consider this statement with the context provided by the rest of Kikuchi’s disclosure in mind. We are persuaded that an ordinarily skilled person would, upon consideration of Kikuchi’s entire disclosure, not interpret this portion of Kikuchi as broadly as the Examiner. A person having ordinary skill in the art would understand this passage as a statement that Kikuchi’s calcium-containing texture modifier could be used in other baked goods in addition to the [breads] and doughnuts Kikuchi describes as preferred embodiments. A person having ordinary skill in the art would not believe that Kikuchi was teaching that the calcium-containing texture modifier could be used in food products other than baked goods, such as the egg portion of Efstathiou.
Some practical Takeaways for Practitioners:
Frame the Context: Emphasize how the reference’s teachings, when viewed as a whole, are contextually limited—even if a particular sentence suggests open-ended applicability. Provide a scope that is beyond the particular embodiments, but not so broad as to extend to the disclosure of the other reference(s) being used in the combination.
Point to Field-Specific Understanding: Argue what a PHOSITA in the relevant field (here, food science) would understand from the reference.
Disarm the “Not Particularly Limited” Trap: When an examiner leans heavily on permissive language like “not particularly limited,” investigate whether that language is actually constrained within a specific domain (e.g., baked goods) - non-limiting does not mean universal.
In sum, non-limiting statements do not necessarily mean that there is no limit at all in terms of the scope of disclosure. Isolated statements do not always turn into blanket authorizations for combination. Stay grounded in the art and the context—for both the examiner and the applicant.