The Written Description
What Does 35 USC § 112 Say About the Written Description?

35 USC § 112 has six paragraphs. The last five are the rules for claims - the first short paragraph (actually just one sentence) contains the rules for the written description. But don't let that short first paragraph fool you - it is loaded with little traps for the unwary - and many practitioners have been caught in those traps. So let's begin by exploring this little paragraph.

    The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor of carrying out his invention.

One way this is commonly interpreted is that there are three requirements here and they are distinct from each other. Look at this way:

This sentence requires that the specification include:

    (A) A written description of the invention;

    (B) The manner and process of making and using the invention (the enablement requirement); and

    (C) The best mode contemplated by the inventor of carrying out his invention.

The Written Description

The opening lines - "The specification shall contain a written description of the invention" - is a requirement distinct from the following words on enablement. To satisfy the requirement, a patent specification must describe the claimed invention in sufficient detail that one skilled in the art can reasonably conclude that the inventor had possession of the claimed invention. Now this is obviously a judgment call, but you can rest assured that examiners often make that judgment call, so in drafting your description you need to do so in full clear and concise language. Underlying this requirement is the legal requirement under patent law that patentees adequately describe their inventions in their patent specifications in exchange for the right to exclude others from practicing the invention for the duration of the patent's term.

I have to sometimes preach this little sermon to new patent applicants because they sometimes feel they should only describe the minimum and conceal the rest. This is the tension between patents and trade secrets. If you want to keep your invention secret - don't patent it. If you want to patent it - spell it out with enough clarity that readers (the examiner and the public) can see that you "possess" the invention.

Possession may be shown in many ways. It may be shown by describing an actual reduction to practice of the claimed invention. Possession may also be shown by a clear depiction of the invention in detailed drawings that permit a person skilled in the art to clearly recognize that applicant had possession of the claimed invention. So because reduction to practice is sufficient evidence of completion, it does not follow that proof of reduction to practice is necessary in every case. It is possible to prove that an invention is complete and ready for patenting before it has actually been reduced to practice.

Written Description Issues

So where can written descriptions issues bite you? Well - obviously if the examiner feels your description as filed lacks clarity. But there are some other instances where this issue can come up.

For example:

    After amendments to claims.When you amend claims to get around an office action rejection of your original claims, the examiner may rule that your amended claim is not adequately supported by the written description as filed.

    When relying on filing date of earlier application.

    Under 35 U.S.C. § 120, the claims in a U.S. application are entitled to the benefit of the filing date of an earlier filed U.S. application if the subject matter of the claim is disclosed in the manner provided by 35 U.S.C. § 112, first paragraph in the earlier filed application.

    When relying on priority of foreign or provisional application.

    Under 35 U.S.C. 119 (a) or (e), the claims in a U.S. application are entitled to the benefit of a foreign priority date or the filing date of a provisional application if the corresponding foreign application or provisional application supports the claims in the manner required by 35 U.S.C. 112, first paragraph. This is becoming more of an issue as more applicants are using provisional applications to establish early filing dates - and they are not providing adequate written descriptions in those provisionals. You may want to review my earlier article on the potential dangers of a provisional.

    There are other subtle aspects of the first paragraph but we will address those at another time. We will next move onto a discussion of the next part of the first paragraph of 35 USC § 112 -enablement.