One of the fundamental rules of patent prosecution is that claims are given their broadest reasonable interpretation (BRI) in light of the specification. The key word, of course, is reasonable. The USPTO is not empowered to assign claim language its broadest conceivable meaning, divorced from the invention described in the application. Rather, claim terms are given their ordinary and customary meaning as understood by a person of ordinary skill in the art, considering the claims, specification, drawings, and relevant context. See MPEP § 2111.

Claim construction is ultimately a question of law, but it can depend on underlying factual inquiries, including how a person of ordinary skill in the art would understand a particular term in the context of the invention. See Teva Pharmaceuticals USA, Inc. v. Sandoz, Inc., 574 U.S. 318, 325–27 (2015). In other words, the meaning of claim language is not always as straightforward as it might first appear.

Two recent PTAB decisions provide an especially good illustration. Both involve language describing a taper extending “from” one point “to” another. In one case, the Board found that the language required a continuous transition extending between the two endpoints. In the other, the Board found that substantially the same directional language did not require continuity at all.

The difference is a useful reminder that patent applicants and practitioners cannot simply assume that they know how a particular phrase will be interpreted. Even seemingly ordinary English expressions can take on different meanings depending on the circumstances.

What does “from A to B” really mean?

Consider the statement: “I am going from California to Maine.”

Does it mean traveling directly from California to Maine? Does it mean flying nonstop? Or does it simply identify the starting point and destination, leaving the route entirely open? A person driving across the country might pass through a dozen states, stop in several cities, and take a circuitous route. The statement remains perfectly accurate.

Now consider a different context: “The road extends from the entrance to the parking lot.” That statement might reasonably suggest a road running between those two locations. But it does not necessarily tell us whether the road is straight, curved, continuous, or interrupted by other features.

Other examples make the point:

• Water flow: A river flows from point A to point B. The endpoints tell us where the water originates and where it ends up, but certainly do not require a straight-line path.
• Temperature: The temperature increases from 40 degrees to 80 degrees. Does that mean it increases continuously, or could it fluctuate along the way before reaching 80 degrees?
• Manufacturing: A component transitions from a rectangular cross-section to a circular cross-section. Does that require a gradual, continuous transformation, or could the component have a rectangular portion, a discrete transition, and then a circular portion?
• Software: Data is transferred from one computer to another. Does that mean a direct connection, or can the data pass through intermediate servers and storage locations?

The phrase “from A to B” does not answer every question about what happens between A and B. Context matters, and two recent PTAB decisions illustrate how different context results in different outcomes.

The fishing rod: “from” one end “to” the other requires a continuous transition

In Ex parte Uribe, Appeal No. 2026-001994 (PTAB Nov. 2, 2026), the applicant appealed rejections of claims directed to a fishing rod. The relevant claim language required:

“wherein the rod blank features a seamless and tapering transition from the approximately triangular prism at the butt-end to the approximately cylindrical tip at the other end.”

The examiner interpreted this language relatively broadly. In the examiner’s view, the limitation required only that a transition occur somewhere between the two ends of the rod. It did not require the transition to extend continuously along the entire length.

The Board disagreed.

The Board agreed with the applicant that the “from” and “to” language identified the endpoints of the transition and required it to extend continuously from the butt end to the tip. Importantly, the Board did not reach that conclusion by looking at the words “from” and “to” in isolation.

The claim expressly recited a “seamless and tapering transition.” The specification reinforced that language, describing a construction in which the rod transitions seamlessly as its body tapers from the triangular prism at the butt end to the cylindrical tip. The drawings also depicted a continuously changing cross-section along the rod.

The Board considered these disclosures in determining how a person of ordinary skill in the art would understand the limitation. In particular, the Board explained that the cross-section progressively changes along the rod, with triangularity decreasing and circularity increasing from the butt end to the tip. There is no portion of the rod along which the cross-section remains constant. That interpretation proved dispositive to the prior-art analysis.

The examiner relied on two references and both disclosed fishing rods having triangular and circular portions. Neither disclosed the continuous transition required by the claim. Instead, each disclosed a distinct transition between portions of the rod, with a substantially constant cross-section along at least part of its length. As such, the Board reversed the anticipation and obviousness rejections.

The takeaway is that the Board was willing to read the “from” and “to” language as defining the full extent of the transition, but it did so in the context of the additional words and a specification and drawings that reinforced that interpretation.

The Intel chip: “from” the top “to” the bottom does not require a continuous taper

Just two days earlier, the Board reached a different conclusion in Ex parte Malatkar, Appeal No. 2026-001608 (PTAB Oct. 30, 2026). This appeal involved Intel’s claims directed to a packaged semiconductor die.

The relevant limitation required a conductive via having:

“sidewalls that taper inwardly from a top of the one of the conductive vias to a bottom of the one of the conductive vias.”

The examiner relied on a prior-art reference that disclosed a multi-tiered conductive via structure. The applicant argued that the particular via identified by the examiner had vertical sidewalls and therefore did not satisfy the claimed taper limitation. The examiner responded that the claimed structure could be understood as an integrated, multi-tiered structure. Viewed as a whole, the structure was wider at the top than at the bottom and therefore tapered inwardly from top to bottom.

The Board agreed with the examiner. In doing so, the Board emphasized that the claim did not require a continuous or linear taper, nor did it exclude a stepped profile. The Board also noted that the specification was silent regarding the term “taper,” providing no particular definition, range, or angular requirement.

The Board found it reasonable to treat the relevant features of the structure as a single via. Looking at the top and bottom of that structure, the distance between the sidewalls was greater at the top than at the bottom. That was sufficient to satisfy the claimed tapering limitation.

The applicant’s argument that the prior-art via had vertical sidewalls did not overcome the rejection because the claim did not require every portion of the sidewall to have a continuously sloping profile.

The Board therefore affirmed the obviousness rejection.

The contrast with Uribe is striking. Both cases involved language describing a taper “from” one location “to” another. But in Malatkar, the Board treated those words as identifying the endpoints for assessing the overall direction of the taper, without requiring a continuous transition between them.

Same words, different results

At first glance, these decisions might seem inconsistent. In one, “from A to B” required a continuous transition. In the other, it did not. But the differences in the claims and specifications help explain the outcomes.

In Uribe, the claim did not merely recite a taper from one end to another. It recited a “seamless and tapering transition.” The specification and drawings reinforced the concept of a progressive change along the entire rod. The Board therefore found that the claimed transition extended continuously between the identified endpoints.

In Malatkar, the claim simply required sidewalls that tapered inwardly from the top to the bottom. It did not say “continuously,” “seamlessly,” or “linearly.” The Board was unwilling to import that additional restriction into the claim.

The Intel decision is particularly instructive because the Board expressly pointed out that the claim did not exclude a stepped profile. Thus, an overall structure that was wider at the top and narrower at the bottom could satisfy the limitation even if the sidewalls did not follow one uninterrupted slope.

Practical tips for patent prosecutors

These cases offer several useful lessons for both drafting and prosecuting patent applications. Of course there are potential downsides to being more clear and express, especially if it turns out that exploiting ambiguity is advantageous during enforcement. There is always balancing and strategy to be considered, so consider the points below if you might want to err on the side of successfully overcoming rejections at the expense of potential design arounds during enforcement.

1. Do not assume ordinary English has only one reasonable interpretation.

Words and phrases that seem perfectly clear to the drafter may not be clear to an examiner or the Board. “From A to B” is a good example. It can identify endpoints without saying anything about the path between them. If the path, sequence, or continuity matters, say so expressly or at least provide an example in which the details are provided.

2. Use modifiers that describe the intended scope.

If the transition must extend along the entire length, considering providing such language at least as an example. The same goes for whether a transition is seamless, smooth, uninterrupted, or progressive. Conversely, if a stepped transition is intended to be covered, consider whether the claims and specification make that clear and exclude a continuous transition.

3. Draft the specification to support the intended interpretation.

The Uribe decision is a good reminder that the specification and drawings can make a significant difference. The applicant benefited from disclosure describing and illustrating the progressive transition along the fishing rod.

Consider whether you want to leave important distinctions to implication when they can be described expressly. Explaining what the claimed feature means, how it operates, and what variations are contemplated, can provide options. If there is a concern as to what claim scope will ultimately be desired, consider providing options in the specification illustrating a range so that if needed, the claims can be narrowed effectively during prosecution.

4. Think about the prior art when deciding how much specificity to include.

A claim that merely requires a feature extending “from” one location “to” another may cover considerably more than the particular embodiment the inventor has in mind. In Malatkar, that broader scope allowed the examiner to rely on a multi-tiered structure having an overall inward taper, notwithstanding the stepped configuration.

Consider the structures likely to be found in the prior art (and in competitor products) and whether the claim language actually distinguishes over them (or covers them). If a continuous taper is important to the invention, claiming only a taper from top to bottom may not be enough.

5. During prosecution, argue from the entire intrinsic record—not just the words you wish had been claimed.

When an examiner adopts an interpretation that seems too broad, identify the particular claim language, specification disclosures, and drawings that make the examiner’s interpretation unreasonable and inconsistent with the specification.

But recognize the other side of the equation: the specification cannot simply be used to import limitations that the applicant chose not to claim. MPEP § 2111 expressly recognizes that distinction. The goal is to establish the broadest reasonable interpretation in light of the specification, not simply the narrowest interpretation that would avoid the prior art.

Ultimately, these decisions reinforce a basic but easily overlooked point: There is risk in assuming that the words in your claims will mean exactly what you think they mean, or in drafting language that is intentionally vague in the hopes that the examiner will apply the interpretation that leads to allowance.