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Last year, the EPO’s Enlarged Board of Appeal (EBA) completely overturned the general approach that the EPO had taken for decades in interpreting patent claims. Instead of insisting that the claims must be inherently clear and interpreted without reference to the description, in decision G1/24 the EBA decided that the description and drawings must always be ‘consulted’ to interpret the claims- and certainly when assessing patentability. Unsurprisingly, significant uncertainty remains as to how G 1/24 is to be applied in practice. That uncertainty has already led to a further referral, G 1/26, which seeks clarification on a number of important issues arising from the decision.

In this article, we examine the questions referred to in G1/26. We also consider the potential potential consequences of the EBA’s answers for different parties. 

Background

The recent G1/24 decision concluded: “The claims are the starting point and the basis for assessing the patentability of an invention under Articles 52 to 57 EPC. The description and drawings shall always be consulted to interpret the claims when assessing the patentability of an invention under Articles 52 to 57 EPC, and not only if the person skilled in the art finds a claim to be unclear or ambiguous when read in isolation.”

However, what “consulting” the description means in practice has been since widely disputed.

The original decision T 0439/22 from which G1/24 was referred, concluded that the specific inclusion of a broader definition of a term in the description is a deliberate act which cannot simply be dismissed when it might be more preferable to do so.

However, there have since been many EPO decisions arriving at divergent conclusions to T 0439/22.

For example, T 2027/23 concluded that "a claim should not be interpreted, based on features set out in embodiments of an invention, as having a meaning narrower than the wording of the claim as understood by the person skilled in the art", while T 1561/23 stated that "G 1/24 does not even explicitly require that the definition of a term from the description must be used for the interpretation of a claim”.

Thus, consulting the description in the in these decisions has been applied more loosely in the style of seeking guidance on how to interpret a term rather than replacing the meaning of a term in the claims with a rigid definition from the description. Our earlier article, summarising the EPO’s case law pre-G1/26, can be found here. This article updates that guidance.

Clearly, there is a need to clarify how and to what extent the description should be referred to for claim interpretation.

Moreover, G1/24 failed to address how always consulting the description for claim interpretation affects how a European patent application or patent can be amended and indeed how this maps onto the prohibition on adding subject-matter beyond the content of the application as originally filed (i.e. Art.123(2)-(3) EPC issues). Indeed, it was precisely this unclear interface between claim interpretation and added-matter gave rise to the referral G1/26.

Thus, we are expecting the outcome of G1/26 to provide much-needed guidance on the practical application of G1/24, in particular, by clarifying the role of the description in assessing added-matter compliance and the extent to which claim interpretation should influence this added-matter analysis.

What is G1/26 about?

The initial referral arose from case T 0873/24, where the opposed patent in question related to a pre-coated metal strip with various elemental weight percentages, as well as the feature: “a ratio of titanium to nitrogen in excess of 3.42”, for which it wasn’t clear whether the ratio relates to weight or moles.

The Opposition Division held that in view of the claim as a whole, the use of weight percentages for the amounts of titanium and nitrogen when calculating the ratio was the only possible interpretation, as supported by the description.

The patentee agreed with this conclusion, arguing that G 1/24 confirmed what was already evident from the claim alone, arguing that this ratio feature of claim 1 had to be read in the context of the rest of the description which referred to weight percentages.

The opponent disagreed, and argued that the basis of the ratio was not specified: in particular, it was not based on weight and that since the application as filed did not support such a generalisation, subject-matter had been added. They further argued that the deletion of the reference to weight percent for calculating the ratio during the grant procedure led to an unallowable generalisation, contravening the strict added-matter requirements. They further argued that G 1/24 actually confirmed the primacy of the claims.

What were the questions referred to the EBA for G1/26?

Question 1:

“May a decision be considered to be "required" for the purposes of Article 112(1) EPC, if the referring Board demonstrates that the point of law in question arises out of the context of the case pending before it and, in the circumstances of the proceedings, it is reasonable for the Board to examine it and decide on it next?”

This is a procedural question concerning when a Board of Appeal may regard a decision from the Enlarged Board as being “required” under Article 112(1) EPC. As such, it is outside of the scope of this article.

Question 2:

 (a) Does the fact that the claims are the starting point and the basis for assessing the patentability of an invention generally preclude a feature which is only disclosed in the description or the drawings of a patent from being read into the meaning of a granted claim, in particular if this leads to a restrictive reading of terms used in the claim?

This question provides the key connection to earlier decision G1/24.

In particular, this question considers whether the statement that the claims are the starting point and basis generally prevents a feature found only in the description or drawings from being read onto a granted claim, especially if that would lead to a restrictive reading on the claim. In other words, does G 1/24 permit the description to be used to impose a limitation that is not apparent from the intrinsic claim wording?

(b) If the answer to question 2.(a) is no: is claim interpretation the result of both reading the claims and consulting the description and drawings as a unitary process and does the claim being the starting point and the basis for assessing the patentability rule out only those interpretations which can be derived from the patent as a whole but would clearly contradict the general technical understanding of the terms used in the claim?

This question essentially considers the converse to 2a, namely whether claim interpretation requires considering claims, description and drawings all together. If so, is claim construction is a “holistic” exercise based on the patent specification as a whole, and where does the boundary lie between using the description to interpret a claim term and impermissibly importing limitations from the description into the claim?

This question is particularly interesting in light of the EPO Guidelines which state: “The description and any drawings are always referred to when interpreting the claims … However, when assessing patentability, the description and drawings cannot be relied on to read into the claim a restrictive feature not suggested by the wording of the claim.”

The Guidelines also state that if the description gives a special broad definition of a claim term, the claim must be interpreted in light of that broad definition, provided the interpretation is technically meaningful. In our view, an interesting further question relates to the converse position, where the description provides a definition of a claim term which includes a restrictive feature which is not found in the claims. Does the fact that the restrictive feature is part of a definition result in it carrying more weight when interpreting the claims?

Thus, G 1/26 will hopefully clarify whether claims are only interpreted from their own wording and whether description-only limitations (particularly restrictive ones) can be used to interpret a claim.

Question 3:

(a) When assessing compliance with Article 123(2) EPC, must a term used in a claim be assessed against all interpretations that make technical sense to the skilled reader on the basis of the claim alone?

This is the added subject matter point. The EPO’s gold standard for the added-matter requirement is that the subject-matter must be “directly and unambiguously derivable” from the application as originally filed.

This question therefore asks whether a term must be checked against all technically sensible interpretations based on the claim wording alone, i.e. beyond just what is referred to in the description.

(b) If the answer to question 3.(a) is no: is it sufficient that only the interpretations of the subject-matter of the claim established against the background of the patent specification as a whole are directly and unambiguously derivable from the application as filed?

This essentially asks whether the opposite approach to 3a should be applied. In particular, should the claim first be interpreted using the claims and description, and then that interpreted subject-matter be assessed as to whether it is directly and unambiguously derivable from the application as originally filed?

Curiouser and Curiouser- Final thoughts and impacts

“Curiouser and curiouser!” Cried Alice (she was so much surprised, that for the moment she quite forgot how to speak good English).”

― Lewis Carroll, Alice’s Adventures in Wonderland / Through the Looking-Glass

Looking at case law developments post G1/24, we are beginning to understand where Alice was coming from, especially now that the G1/24 decision has bled into the realm of added subject-matter. However, we do think that the questions referred to the EBA in G1/26 are sensible.

The answer to Question 2 will help clarify how much the description is actually relied on with regards to the meaning of terms in claims. Indeed, if the answer to question 2a is “yes” then this means claims cannot be narrowed by features only found in the description, meaning the literal wording of the claim is more important. In the T 0873/24 case this means the opponent’s argument could prevail in preventing proprietors from narrowing the ratio feature to referring to weight percentage, based on the description.

On the other hand, if the answer to 2b is “yes”, then claim interpretation is essentially “unitary”, meaning where a term appears broad in isolation but every embodiment points to a specific meaning, the description could have a stronger role in shaping interpretation. In T 0873/24, this could mean the weight percentage could be imported onto the interpretation of the ratio feature. This could make novelty and inventive-step attacks less straightforward for the opponent, because the actual scope of the claim may become harder to delimit.

Moving onto question 3, if the answer to 3a is “yes”, then all reasonable interpretations derivable from the claim wording must be considered and the corresponding support found in the application as filed. Thus, an opponent would only need to find one such interpretation which isn’t in the specification as filed to have a potentially successful added-matter attack.

Conversely, if the answer to 3b is “yes”, then only the interpreted subject-matter is tested against the application as filed, eliminating the opportunity to include other, additional interpretations. In effect, the “context” of the application here is key to determining added-matter.

The answer to these questions will no doubt also impact how practitioners draft specifications. Indeed, care may need to be taken to ensure appropriate restrictions are within the claim language itself and not plucked from the embodiments of the description, meanwhile also ensuring there are suitably clear definitions in the description. Hopefully, G1/26 will provide some ‘concrete’ answers which will provide more certainty on how to draft effective patent applications for the EPO. In the meantime, there is uncertainty, and our advice from our earlier article is unchanged: it would be unwise to think of G1/24 as a ‘get out of jail card’ to put right issues with patentability and claim drafting and instead practitioners should aim to draft claims which are clear in their own right.

If you would like to discuss the best way to provide clearly drafted claims and whether or not to include definitions in the description of your patent or patent application, please contact us. Wynne Jones can advise on effective strategies for drafting patent applications carefully and in line with EPO practice.

Keywords: patents, European Patent Office (EPO), description, claims, Enlarged Board of Appeal (EBA), G1/24, claim interpretation, G1/26, added-matter