Patent Drafting Tip: A comma affects meaning of items in list

By James Yang
March 6, 2017

CommaThe purpose of the comma and how the comma might change the meaning of the sentence was debated when the America Invents Act (AIA) was enacted in 2013. Because of a comma, the meaning of the Act was debated and was interpreted at least by the U.S. Patent and Trademark Office and at least one district court to overturn existing case law in relation to whether secret offers for sale would qualify as on-sale bar to patentability. Also, the comma was used to interpret the meaning of a list of items as discussed below. As such, as patent attorneys, being aware of the effect on the meaning of a sentence by adding or removing a comma in a patent application or patent claim would be prudent.

With respect to the AIA, the specific statutory provision affected by the comma was AIA 35 U.S.C. § 102(a)(1) which states that:

“a person shall be entitled to a patent unless the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.” (Emphasis added).

The issue was whether the comma in the phrase “, otherwise available to the public” meant that the phrase also modifies the phrase “on sale.” If the phrase “, otherwise available to the public” does modify the “on sale” phrase then offers for sale of a product or service not offered to the public but made in secret would no longer be a bar to patentability.

Previously, secret offers for sale were considered a bar to patentability that prohibited an inventor from securing a patent if such secret offer for sale was made more than one year before the filing of a corresponding patent application. See MPEP 2133.03; Hobbs v.United States, 451 F.2d 849, 859-60, 171 USPQ 713, 720 (5th Cir. 1971).

The USPTO promulgated rules that explained their interpretation of § 102(a)(1). They interpreted the “, or otherwise available to the public” phrase as also modifying the “on sale” phrase in AIA § 102(a)(1) so that a secret offer for sale is no longer a bar to patentability under the new statute. See MPEP 2152.02(d).

At least one District Court opinion has also followed the interpretation of the phrase “, otherwise available to the public” as also modifying the “on sale” phrase consistent with the USPTO. Helsinn v. Dr. Reddy’s and Teva (D.N.J. 2016).

Because of the focus given to the comma in this widely discussed “on sale” issue, awareness should be raised for the use of the comma in drafting patent applications and especially in drafting patent claims. A frequent claiming practice used in many patent application is to list optional parts within a group. For example, the patent application may recite “by way of example and not limitation, it is also contemplated that the following materials may be used to fabricate the device: X, Y, Z and other [insert characteristic of the material] material.” In doing so, the patent drafter should be aware that the last phrase may also modify the items in the list that come before it.

3Form, Inc. v. Lumicore, Inc. (Fed. Cir. 2015, nonprecedential) is an example of how the court interpreted the patent because of the comma. In particular, the court interpreted the claimed phrase “the object splits, cracks, or otherwise compresses into an unnatural conformation.” In doing so, the court found that the phrase “unnatural conformation” modified not only “compression” but also modified “splitting” and “cracking” in the same sentence. This was all due to the comma used in the sentence. In fairness, the patent description made clear that the splitting and cracking arose from compression so the claim construction was consistent with the patent disclosure. But the court noted that the “most natural reading of this clause was that ‘otherwise compresses’ is a catch-all that sweeps in other deformative acts, including those specifically introduced earlier in the series–splitting and cracking.

The words that we, as patent attorneys use are important and ever more so in a patent application. For this reasons, it would be prudent to be aware that utilizing a comma can change the meaning of a sentence or phrase. Patent counsel should be aware that the presence or absence of the comma in a list may affect the way that the list is interpreted and make a conscious decision to either add or remove the comma based on the desired end result intended by the patent drafter. Don’t let the comma have an unintended consequence. To make the meaning of the list clear, the patent drafter may want to consider adding an additional sentence to indicate whether the last item in the list does or does not modify the items in the list that came before it, or change the structure of the language to make the meaning more clear.

The Author

James Yang

James Yang is a patent attorney and helps inventors and mid-sized businesses secure intellectual property protection for their inventions. He also publishes articles relating to the patent system at OC Patent Lawyer and is a a principal at Stetina Brunda Garred and Brucker.

Warning & Disclaimer: The pages, articles and comments on do not constitute legal advice, nor do they create any attorney-client relationship. The articles published express the personal opinion and views of the author as of the time of publication and should not be attributed to the author’s employer, clients or the sponsors of Read more.

Discuss this

There are currently 4 Comments comments.

  1. Anon March 6, 2017 8:00 am

    Well stated – thank you

  2. Gregory Lars March 6, 2017 9:22 am

    Not only is the comma indicative of “otherwise available to the public” modifying both “public use” and “on sale,” but the use of a second “or” helps support your assertion as well.

    The use of the word “or” twice shows 102(a)(1) is comprised of a three part list where the third part is a three part sub-list. Patent attorneys should be especially familiar with how sub-lists may be utilized within an overall list because it is frequently used when writing claims. For example:

    I claim the article X, which comprises:
    B, and
    C, wherein C comprises:
    E, and

    The situation is similar in 102(a)(1), although the preposition is not “and,” but is instead “or.” Additionally, C is not generally defined, but instead is immediately listed as a sublist. If indented similarly, 102(a)(1) should read:

    A person shall be entitled to a patent unless the claimed invention:
    was patented,
    described in a printed publication, or
    in public use,
    on sale, or
    otherwise available to the public before the effective filing date of the claimed invention.

    Looking at it this way, it becomes more clear that “otherwise available to the public before the effective filing date of the claimed invention” modifies “in public use” and “on sale” because of the use of the second “or” and the placement of the commas.

    Interestingly enough, the phrase “otherwise available to the public” does not modify “was patented” or “described in a printed publication.” I originally thought that it did not need to, as all patents and printed publications were public and so there was no express need for “otherwise available to the public” to modify the first two phrases. But that’s not entirely true. Some patents are subject to secrecy orders, and those patents may still preclude other patent applications from becoming issued patents, regardless of whether they were made public. Thus, now, I think the current formatting of 102(a)(1) was VERY intentional.

    Hope this helps,


  3. Gregory Lars March 6, 2017 9:24 am

    It seems the indentation of the items in my above post did not show properly when I posted it as a comment.

    That’s a bummer.

    But, if anyone is wondering.

    In the first list, “D, E, and F” should all be indented.”

    In the second list, “in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention” should all be indented as well.

  4. Paul F. Morgan March 7, 2017 9:51 am

    These two D.C. interpretations of AIA 102 are also consistent with other aspects [and commentaries] suggesting an intent to eliminate “secret prior art.”