The Minutes published following a recent Board of Appeal oral proceedings indicate that a further referral will be made to the Enlarged Board of Appeal. It looks like the referral will seek guidance as to whether and to what extent the decision issued in G 1/24 should apply when assessing added subject matter, i.e. should the description be consulted to interpret the claims when assessing added subject matter?
Background
The decision in G 1/24 said that the description should always be consulted when interpreting the claims. This prompted a further referral to the Enlarged Board of Appeal: G 1/25 poses questions regarding whether the description should be amended to be consistent with amendments made to the claims. This should make it easier to interpret the claims as it should remove any inconsistencies that might give rise to ambiguity.
Now a second referral looks imminent. This arises because the case under consideration in G 1/24 was concerned with interpreting the claims for an assessment of novelty and inventive step. In the latest case, T 873/24, it is added subject matter that is under consideration. Hence, the Board of Appeal in T 873/24 are seeking guidance as to whether the direction to consult the description when interpreting claims applies also to considerations of added subject matter.
Outline of T 873/24
This concerns a divisional application in opposition proceedings. The subject matter of the opposed patent concerns aluminium-coated steel strips. Claim 1 of the Main Request specified a ratio of titanium to nitrogen in the base steel.
However, the ratio did not indicate any units to be used in determining the ratio: it merely said, “wherein the ratio of titanium to nitrogen is in excess of 3.42”. The claims in the parent and grandparent applications specified a ratio by weight %: they said the ratio of titanium to nitrogen in the steel sheet in weight % is in excess of 3.42. However, other units are possible. For example, it could be a ratio of moles rather than weights.
The description provided two paragraphs mentioning the ratio of titanium to nitrogen. The first specified a ratio by weight % while the second did not specify any units.
The Board of Appeal was considering whether the change in language to omit reference to weight % amounted to added subject matter.
The comments of the Board of Appeal
As is normal, the Board of Appeal offered a preliminary opinion ahead of the oral proceedings. In this opinion, they noted that the ratio of titanium to nitrogen was now open ended, unlike the original application. The Board of Appeal also indicated that they did not follow the Opposition Division’s belief that the preceding part of claim 1 and the description implied that the ratio could only mean a ratio by weight %. Consequently, the Board of Appeal indicated that they believed claim 1 added subject matter.
The patentee subsequently filed written submissions including an argument that the description should be consulted when interpreting the claim. The patentee concluded that consulting the description made it clear that the ratio in claim 1 was limited to a ratio by weight %.
The opponent responded, citing the decision in T 405/24 that rejected an argument that, following G 1/24, where multiple technically sensible interpretations of a certain claim feature exist, the one which is supported by the patent description should prevail. T 405/24 also noted that established case law teaches us that all technically reasonable interpretations of a claim feature are to be taken into account when assessing added subject matter.
In the Minutes, the Board of Appeal noted several issues affecting the added subject matter determination. These included:
The Board of Appeal concluded that the case hinged on the question of how to apply G 1/24 which they believed to be a point of law of fundamental importance. Consequently, the Board noted that they were minded to refer the case to the Enlarged Board of Appeal.
Discussion
The questions to be referred to the Enlarged Board of Appeal have yet to be formulated and so we can only speculate on what they might be. I assume they will include a general question as to whether the description is to be consulted when interpreting the claims in an assessment of added subject matter in accordance with G 1/24 and also one or more questions seeking guidance on how G 1/24 should be applied.
In terms of any decision, the referral arises because of the consideration of added subject matter as opposed to novelty and inventive step as in G 1/24. However, the assessment of added subject matter is similar to that of novelty, i.e. an amended claim can be considered to add subject matter if it is considered novel over the disclosure of the application as filed. Consequently, it would not be surprising if the EPO found that the decision of G 1/24 should apply also to assessments of added subject matter.
I expect the EPO will confirm the primacy of the claims to apply also to assessments of added subject matter. Claims often have a clear meaning when read in isolation and this should not be ignored when it is contradicted by the description. I suspect that the EPO will maintain their position that all technically reasonable interpretations of a claim feature are to be taken into account when assessing added subject matter – and also that the description should not be given an undue influence to rule out any of these technically reasonable interpretations.
The Board of Appeal in T 405/24 provided comments regarding the application of G 1/24 when assessing added subject matter which I imagine would influence the Enlarged Board of Appeal. The Board in T 405/24 noted that G 1/24 provides no indication that “consulting” the description could translate to adopting a claim interpretation which ensures that the disputed feature is originally disclosed and thus necessarily complies with added subject matter requirements. The Board commented that such an approach which inherently assumes that there may be only one “correct” interpretation of a claim feature, namely the one derivable from the original description as its intended meaning, would not lead to an objective added subject matter assessment and thus jeopardise legal certainty.
The Board in T 405/24 said that such an approach would be tantamount to interpreting a claim feature such that, in the end, virtually no violation of the added subject matter requirements within the meaning of the well-established “gold standard” could arise. It is easy to envisage an amendment to a claim that generalises the wording of a paragraph from the description: if the claim has to be interpreted to mean what is disclosed in the description, then there is no need to check for added subject matter making the EPO’s gold standard test redundant.
There are no guarantees that the Enlarged Board of Appeal will admit the referral. If the Enlarged Board does, it will be interesting to see how it is handled with respect to the referral in G 1/25. There is clearly an interplay between the description and claim interpretation which applies both to added subject matter and novelty/inventive step assessments.
Moreover, G 1/24 might be exploited by patent proprietors to argue for narrow interpretations of claims to overcome added subject matter and/or novelty issues, and yet avoid amending the claim language to leave the door open for arguing for a broader interpretation in any subsequent infringement proceedings. The EPO may push for consistency between the description and claims to avoid this and so provide clarity to third parties.
Takeaway
It will be interesting to see what questions are referred to the Enlarged Board of Appeal and then to see if the referral is admitted.
In the meantime, best practice in drafting and prosecuting patent applications should remain unchanged. While patent applications should be drafted and prosecuted with an eye to securing the broadest possible protection for clients, the need to provide strong basis for narrowing amendments must be borne in mind.
The opportunities to argue for claim interpretations that deviate from the wording of the claims may become more limited. Providing sound basis to allow amendments to claims to ensure they clearly recite an intended meaning remains important, as too does including basis for alternative amendments to allow room to manoeuvre around unknown prior art.
For further details, please contact Nigel Tucker or your usual Boult advisor.
