What Is a Written Description in a Patent?

A critical aspect in patent drafting is the “written description requirement” (35 USC §112(a)). This is a standard feature of all patent systems, which requires that claims be “supported” by the specification. Shortfalls in meeting the written description requirement are common mistakes that can get inexperienced patent attorneys and “do-it-yourself-ers” into trouble.

Written description in a patent requires an element of expertise that typically only an experienced patent attorney can properly handle. The point of the written description requirement is that all elements in the claims need to be described and discussed the specification, i.e., the body, of the patent.

The basic written description requirement has two different aspects that non-experts should know about:

Enablement: This means that the invention is described in sufficient detail that a person of skill in the art can practice the invention (i.e., make the thing or get the desired result) without “undue experimentation.”

Possession: The inventor must have “possessed” the invention at the time of filing. It is not necessary to have actually made the thing (called “reduction to practice”), or to show examples. However, the inventor must describe the invention in sufficient detail that a person skilled in the art can visualize or recognize the invention. A mere wish or plan is insufficient.

So, there is more to filing a patent than getting the claims right. The specification requires careful attention to detail to ensure that the invention is described with a level of specificity required by the written description requirement.

To help you understand this, consider a trivial example illustrating how inventors can get into trouble with the written description requirement. Suppose you make a brilliant and innovative invention for washing dishes. You prepare a patent application and claims on this method, and at the last minute, you realize this invention can also mop floors. So you add a few claims to mopping floors. If you go ahead and file this patent application, you will have a written description problem. The claims to mopping floors are not supported in the specification.

You may ask yourself how something like this can happen. In this trivial example, the problem is obvious. The inventor needs to either take out mopping floors, or add a few paragraphs discussing mopping floors to the specification.

But in real-life patent prosecution, as patent examiners make objections based on prior art, patent applicants may try to add claim limitations in an effort to satisfy these objections, to tweak the invention and distinguish the prior art. It is very easy to add language that is not fully supported in the specification, and create a new set of problems with the patent examiner.

When this happens, all hope is not lost! We have ways of fixing these problems that can include, for example, filing a continuation-in-part patent application which provides a mechanism for adding additional language to a patent specification.

The key point is that an expert at patent drafting is more likely to spot these issues before they come up and advise the inventor which details to flesh out in the specification, to ensure that the claims are clear and concise during the patent drafting stage and avoid serious prosecution difficulties.

One way we help avoid written description problems during patent application preparation is by drafting the claims first, and then the specification. That keeps the invention on track from the beginning in a focused process.

Look to us to get this key aspect of patent prosecution right the first time.


Andrew H. Berks
Direct: 646-797-2952
Mobile: 845-558-7245
Skype: andrew_berks
aberks@counsel4creatives.com