I have read that in patent drafting you have to be consistent with the terms you use. For example, if you refer to a “motor” in one place don't refer to it as “engine” in another place. What about word order? If in one place I talk about a “estimate of the orientation of the device” and in another place I talk about “orientation estimates”, would that rise any problems? Should I every time write “estimate of the orientation”?

I think at some point I have made this type of change to avoid sentences like “the A of the B of the C of the E”

  • @George Your comment sounds like a reasonable answer. Best to post it as such. Thanks. Feb 17, 2013 at 22:21

2 Answers 2


Probably not an issue in the specification but you need to be very careful in claim wording. Otherwise you get "lacks proper antecedent basis" in your office action.


As an alternative answer, courts generally presume that different words in a patent application have different meanings. CAE Screenplates, Inc. v. Heinrich Fiedler GmbH & Co. KG, 224 F.3d 1308, 1317 (Fed. Cir. 2000). This canon has been applied not only to the use of different words in claims, Id., but also to the use of different words in the written description. Chicago Board Options Exchange, Inc. v. International Securities Exchange, LLC, 677 F.3d 1361 (Fed. Cir. 2012). Many patent attorneys pay careful attention not to interchange different words when describing the same feature. Otherwise, as demonstrated in these two cases, using different words can cause a court to reach an unintended determination of what the patent covers. Even switching word order, changing an adjective, or converting a word to a different part of speech could lead to the same result.

It is an unfortunate consequence that using precisely the same term leads to awkward syntax, such as your string of infinitive phrases.

  • Very complete answer!
    – George White
    Feb 18, 2013 at 21:44

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