It is surprising to read a Federal Circuit case on patent claim construction, delving deeply into the difference between â€œandâ€ and â€œorâ€, referencing Stunk & White â€” and incorrectly writing â€œofâ€ when the court meant to use â€œorâ€ in a quote from Struck & White!
The Federal Circuit wrote: â€œA common treatise on grammar teaches that â€˜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.â€™ William Strunk, Jr. & E.B. White, The Elements of Style, 27 (4th ed. 2000).â€ SuperGuide Corp. v. DirecTV Enterprises, Inc., 358 F.3d 870, Â¶ 68 (Fed. Cir. 2004).
â€œAn article of a prepositionâ€ â€” upon reading this I wondered: is this some rule of grammar that I never learned? A preposition states the relationship between objects, and does not require an article. So, I went to the source â€” Strunk & White. And here is what it actually says: â€œ[a]n article or a preposition applying to all the members of a series must either be used only before the first term or else be repeated before each of them.â€ Strunk & White, The Elements of Style, page 27, emphasis added.
Of course, itâ€™s a typo in the Federal Circuit case. BUT, this misquote of Strunk & White has been repeated in scholarly articles analyzing the use of â€œorâ€ in patent claim construction. Iâ€™m not sure how â€œorâ€ what these authors were thinking when they read about an â€œarticle of a prepositionâ€ but they certainly werenâ€™t thinking about grammar!
PATENT CLAIM CONSTRUCTION
Now that this confusion had been cleared up, here is a brief summary on the Federal Circuitâ€™s interpretation of â€œORâ€ in patent claim drafting:
â€“ OR â€“ INTERPRETATION #1 â€“
â€œOrâ€ may mean: A or B, but not A and B.
If a claim uses â€œorâ€ it may be interpreted to mean a choice between two items, but not both. Kustom Signals, Inc. v. Applied Concepts, 264 F.3d 1326 (Fed. Cir. 2001). The Kustom Signals court stated: â€œThe district court construed the term â€˜orâ€™ â€¦ to mean â€˜a choice between either one of two alternatives, but not both.â€™â€ Kustom Signals, 264 F.3d at 1330. The court held that â€œThe prosecution history requires that â€˜orâ€™ means the operatorâ€™s choice between search for the strongest or fastest target speed, but not both. The district courtâ€™s claim construction is affirmed.â€ Kustom Signals, 264 F.3d at 1331-1332.
â€“ OR â€“ INTERPRETATION #2 â€“
Or (pun intended) â€œorâ€ may mean: A, or B, or A and B. See, Brown v. 3M, 265 F.3d 1349 (Fed. Cir. 2001). In Brown, the court held that â€œorâ€ meant A, or B, or C, or any combination of A, B and C.
Lesson learned: be clear in claim drafting, and be careful when using the word â€œorâ€.