“Providing a complete description of the structural features, the corresponding functions, and the correlation between the two, will later allow the EPO attorney to leverage those features before the EPO to prove compliance with the clarity requirement.”

When drafting Patent Cooperation Treaty (PCT) applications, or applications intended to be prosecuted abroad, a U.S. drafter inevitably faces the challenge of providing a description in line with the requirements of different jurisdictions.

By the time feedback is received from the foreign patent offices, it will be too late to make any adjustments, and important aspects of the invention may inadvertently be lost.

The challenge might feel impossible when dealing with the requirements of the European Patent Office (EPO), as the European Patent Convention (EPC) regulations on written description are framed in a way that is fundamentally different from U.S. regulations.

Written Description Versus Clarity

For example, the requisites of providing an adequate description and notice of the metes and bounds of the claimed invention are framed in the United States as separate requirements (written description and definiteness respectively) with different legal bases (35 USC 112(a) for written description and 35 USC 112(b) for definiteness respectively).

In the EPC, those requisites are instead intertwined in the clarity requirement of Art. 84 EPC which indicates that “the claims shall …be clear and concise and be supported by the description.”

Advantageously for U.S. applicants, the EPO Guidelines provide criteria to evaluate compliance of a description with the requirements of Art. 84 EPC, which have strong parallels with the criteria used in the United States to evaluate written description. In particular, the EPO Guidelines state that:

“The applicant should be allowed to cover all obvious modifications of, equivalents to and uses of that which he has described. In particular, if it is reasonable to predict that all the variants covered by the claims have the properties or uses the applicant ascribes to them in the description, he should be allowed to draw his claims accordingly.”

These EPO “variant” criteria provide strong parallels with the “identifying characteristics” frequently applied to evaluate written description/support in the US system. In particular, MPEP 2163.II.3 indicates that

“[a]n applicant may also show that an invention is complete by disclosure of sufficiently detailed, relevant identifying characteristics … i.e., complete or partial structure , other physical and/or chemical properties , functional characteristics when coupled with a known or disclosed correlation between function and structure , or some combination of such characteristics.”

And, as an explanation of “identifying characteristics”, MPEP 2163.02 indicates by example:

“If the application … does not disclose the complete structure (or acts of a process) of the claimed invention as a whole , determine … other relevant identifying characteristics … For example, if … strong correlation between structure and function , one skilled in the art would be able to predict … the structure of the claimed invention from a recitation of its function ”

The strong parallels between the U.S. “identifying characteristics” and the EPO “variant” criteria is evident from the following side-by-side comparison:

– EPO: if it is reasonable to predict that all the variants covered by the claims have the properties or uses the applicant ascribes to them in the description, [then] he should be allowed to draw his claims accordingly. – USPTO: if a strong correlation between structure and function , one skilled in the art would be able to predict … the structure of the claimed invention from a recitation of its function. ”

Therefore, the EPO variants covered by the claims, and related properties or uses, essentially provide an EPO version of the U.S. identifying characteristics.

The case law of the EPO Boards of Appeal also provides criteria which makes direct reference to elements of the description and claims and, in particular, to structural and functional features of the invention as described/claimed.

A Powerful Tool

This correspondence makes the use of “identifying characteristics” a very powerful tool in the hands of a U.S. drafter who is drafting an application intended to be prosecuted before the EPO.

In particular, providing a complete description of the structural features, the corresponding functions, and the correlation between the two, will later allow the EPO attorney to leverage those features before the EPO to prove compliance with the clarity requirement of Art. 84 EPC.

Interestingly, relying on structure/function and relationship between the two can also minimize later issues under Art. 123(2) EPC, the most dreaded provision of the EPC for U.S. users. This will be discussed further in a separate article.