“A more careful look at Rule 42 of the European Patent Convention (EPC)—the legal basis of EPO background section practice—reveals that extremes are really not necessary.”

Preparation of the background section of a specification that complies with the requirements of both U.S. Patent and Trademark Office (USPTO) and European Patent Office (EPO) requirements is a classic conundrum for patent drafters seeking to file an application in both jurisdictions via the Patent Cooperation Treaty (PCT) or direct filings.

In U.S. patent applications, statements made in the background section can be considered an admission of prior art, regardless of whether the admitted prior art would otherwise qualify under 35 U.S.C. 102 and regardless of any disclaimer made.

Additionally, statements made in the background section of an issued U.S. patent can not only be used against expert testimony that describes the prior art differently and during claim construction, but also can have a limiting effect on claim interpretation.

As a consequence, discussion of deficiencies in the prior art can be interpreted as a disclaimer of the related features and therefore can severely (and often inadvertently) limit the interpretation of the claims.

In contrast, statements made in the background section of EPO applications that discuss deficiencies and technical problems present in the prior art are expected to be included in order to enable the reader to understand the technical contribution to the art made by the invention as claimed.

In particular, according to EPO practice, the applicant is expected to discuss the technical problem solved not just in view of the closest prior art at filing (subjective technical problem), but also, more importantly, in view of the prior art cited during prosecution in the context of the problem-and-solution approach (objective technical problem).

Accordingly, applicants drafting applications to be filed at the EPO tend to provide a heavy background section with discussions of cited documents, related deficiencies and problem solved and later adjust it in view of the objective technical problem in view of the objective technical problem arising during prosecution.

On the other hand, in view of the serious and often inadvertent consequences of lengthy backgrounds, many U.S. practitioners limit the background to a bare minimum or, in some cases, completely omit the inclusion of any background section in their application, based on an interpretation of the law that suggests that presence of such background section is optional (see Chisum on Patents/37 CFR 1.77).

Determining Best Practices

What constitutes best practice in this scenario and how the two practices can be harmonized is controversial.

One thing is certain: for U.S. applicants or for foreign applicants having interest in the U.S., any best practice must respect the requirements of the U.S. system while avoiding any draconian solutions, such as that of preparing two different applications for the two jurisdictions.

A more careful look at Rule 42 of the European Patent Convention (EPC)—the legal basis of EPO background section practice—reveals that extremes are really not necessary. Rule 42 says:

The description shall: .. (b) indicate the background art which, as far as is known to the applicant, can be regarded as useful to understand the invention, draw up the European search report and examine the European patent application, and, preferably, cite the documents reflecting such art…

This language limits the background reference to art “useful to understand the invention” and defines the citation of documents as something applicants should “preferably” do.

In line with such interpretation, in EPO T 2321/08 of 11.5.2009 the Boards of Appeal of the EPO have indicated that Rule 42 EPC “does not put a stringent obligation on the Applicant to acknowledge prior art known to him, and to cite documents known to him reflecting this prior art, already at the time of filing the application”.

Therefore, an applicant drafting for both U.S. and EPO jurisdictions can prepare a background section in compliance with the U.S. practice and then wait for the end of the EPO prosecution to make any statements concerning documents cited in connection with the objective technical problem, thereby using the EPO practice related to the objective technical problem to their advantage.

Additionally, when discussing the closest prior art, the applicant has the option to limit the statements to only what is “regarded as useful to understand the invention” which, in practice, results in not needing to make a lengthy discussion on the deficiencies of the document.

Accordingly, while the drafting strategy should be always tailored to the specific needs of the applicant and the specifics of the innovation at hand, the above suggested approach should not jeopardize the EPO prosecution and should protect the applicant and the innovation in the United States according to current best practice.