What does “A” mean in a patent application?

What does the little word “a” mean in a patent application?

It’s surprisingly unclear.

In the recent case of Niz-Chavez v. Garland, US Supreme Court decided that “a” meant “one.” That might seem obvious, but the government in that case contended that "[t]he indefinite article `a' is often used to refer to something that may be provided in more than one installment.”

The Court noted that

The government observes, for example, that a writer can publish "a" story serially, or an author may deliver "a" manuscript chapter by chapter. …The dissent offers its own illustrations, highlighting that "a job application" and "a contract" also can be prepared in parts. … So even if IIRIRA speaks repeatedly of "a" notice to appear, the government and dissent contend, it remains possible that Congress meant to allow that notice to come over time and in pieces.

The trouble with this response is that everyone admits language doesn't always work this way. To build on an illustration we used in Pereira, someone who agrees to buy "a car" would hardly expect to receive the chassis today, wheels next week, and an engine to follow.

Normally, the Court continued,

indefinite articles (like "a" or "an") precede countable nouns. The examples above illustrate the point: While you might say "she wrote a manuscript" or "he sent three job applications," no one would say "she wrote manuscript" or "he sent job application." … By contrast, noncountable nouns—including abstractions like "cowardice" or "fun"—"almost never take indefinite articles."

In the patent context, the Federal Circuit held in the case of KCJ Corp. v. Kinetic Concepts, Inc. “a” can mean “one” or “more than one.”

The claim at issue included the phrase “1. An air flotation, ventilated mattress apparatus comprising: … a lower, continuous, inflatable chamber….”

The court asked whether this limited the number of chambers to only one, or whether it could include more than one chamber. It noted that

an indefinite article “a” or “an” in patent parlance carries the meaning of “one or more” in open-ended claims containing the transitional phrase “comprising.” … Unless the claim is specific as to the number of elements, the article “a” receives a singular interpretation only in rare circumstances when the patentee evinces a clear intent to so limit the article. … Under this conventional rule, the claim limitation “a,” without more, requires at least one.

The Federal Circuit reached a similar conclusion in the case of Baldwin Graphic Sys., Inc. v. Siebert, Inc., in which a patent claim referred to “a pre-soaked fabric roll.”

The Federal Circuit noted that “a” is to be construed as “‘one or more’ in open-ended claims that include the phrase ‘comprising.’”

But then the Federal Circuit seemingly reached the opposite conclusion in another case.

In Harari v. Lee, a claim included the phrase “a) accessing a number of control gates and accessing a bit digit line, thereby activating a said number of memory cells … .”

The court noted that “Baldwin… does not set a hard and fast rule that ‘a’ always means one or more than one,” but “[w]hen the claim language and specification indicate that ‘a’ means one and only one, it is appropriate to construe it as such even in the context of an open-ended ‘comprising’ claim.”