6. Interprétation des revendications

In T 873/23 claim 1 as granted was amended with respect to claim 1 as originally filed inter alia by Feature 1.5x, specifying that, for an electric coil cooktop and an electric glass ceramic cooktop, the control device was configured to control the power level of the cooktop "by turning the heating element continuously on and off". It was common ground that there was no literal basis for "continuously" in the context of "turning the heating element on and off" in the application as filed. However, the board observed that there were other occurrences of the term "continuously" in the description (both as filed and as granted) and in claim 1 as granted in the context of monitoring/sensing the temperature and calculating a rate of change of the sensed temperature. The parties agreed that, according to the patent, in these occurrences "continuously" meant "periodically", albeit with different time periods for monitoring and calculating.

The board agreed in principle with the "two-step approach" for the assessment of added matter set out in the Catchword of T 367/20. The patent claims first had to be interpreted in order to determine the subject-matter they contained after the amendment. They were interpreted in line with G 1/24, which states, in the context of assessing the "patentability of an invention under Articles 52 to 57", that the claims are the starting point and the basis for the assessment, and the description and drawings are always to be consulted to interpret the claims. The board considered this to be true not only for the question of "patentability of an invention under Articles 52 to 57" but also for the issue of Art. 123(2) EPC. In a second step, it had to be assessed whether the subject-matter of the amended claim contained subject-matter which extended beyond the content of the application as filed. In this regard, in accordance with G 2/10, the decisive factor was whether the skilled person was presented with new technical information after the amendment..

The board disagreed with the two interpretations of Feature 1.5x submitted by the appellant (patent proprietor). The board considered that the only convincing interpretation of the expression "by turning the heating element continuously on and off" was that of periodically turning the heating element on and off (at fixed intervals) as submitted by the respondent, which included pulse-width modulation of the heating element in accordance with a predetermined duty cycle. In reply to the appellant’s argument that this interpretation "was not in line with the disclosure in the patent", the board explained that, according to T 367/20, a claim feature had to be interpreted not in isolation but in the context of the whole document it formed part of. This was, however, to be done by taking due account of the primacy of the claims (see also T 1473/19). This was also in line with G 1/24, which states that the "claims are the starting point and the basis" (see also UPC_CoA_335/2023, second Headnote, according to which the claims were the "decisive basis").

The board observed that the application as filed disclosed embodiments in which the heating element was controlled on the basis of a duty cycle and was thus "continuously" turned on and off. However, even in the algorithm using duty cycles, different duty cycles and phases of keeping the heating element "on" for a specific period of time were employed. The heating element was thus not always "periodically" turned on and off, and the "continuity" of the duty cycle was interrupted under certain conditions. As claim 1 as granted did not include these more specific aspects of the power control for the electric glass ceramic cooktop of the application as filed, and as the application as filed did not disclose a periodicity throughout the algorithm, the amendment in Feature 1.5x was at least an unallowable intermediate generalisation of the original disclosure. Moreover, the application as originally filed did not contain a corresponding disclosure (power control algorithm based on a duty cycle) for the electric coil cooktop (Feature 1.5a). Accordingly, the combination of Feature 1.5x with Feature 1.5a extended beyond the content of the application as filed..

The maintenance of the patent as granted according to the main request was thus prejudiced by the ground of opposition under Art. 100(c) EPC. Since none of the claim requests was allowable, the appeal was dismissed.

In T 1849/23 claim 1 as granted was directed to a trailer oscillation and stability control device comprising, among other things, an angular rate sensor positioned and configured to measure the rate of angular trailer deflection about a hitch pivot point and to generate corresponding angular trailer deflection rate signals.

In response to a novelty objection based on a prior art document, which disclosed a yaw rate sensor on the trailer, the respondent (patent proprietor) had argued that the absolute yaw rate and the rate of angular trailer deflection about the hitch pivot point were distinct physical quantities, even if their values coincided during straight-line vehicle operation. These two physical quantities did not become the same physical quantity simply because their values coincided in one specific condition. The claim clearly defined the angular rate sensor as being configured to measure the rate of angular trailer deflection about a hitch pivot point.

The board agreed that, when the claim was read in isolation, that feature could be read literally such that the angular rate measured by the sensor was the rate of the angle made by an axis passing through the hitch pivot point with respect to a reference axis. However, in accordance with G 1/24, claim interpretation required taking into consideration the wording of the claim and the content of the description..

The board observed that the patent disclosed a gyroscope sensor (i.e. a sensor for measuring the yaw rate) as the only specific implementation of the claimed angular rate sensor. This was not only denoted in figures 3 and 4 as a "gyro", but the description of the preferred embodiments of the invention also described the sensor as a raw angular rate sensor, i.e. a sensor measuring absolute yaw rate. A measure of the yaw rate of the trailer coincides with the rate of the angle made by an axis passing through the hitch pivot point with respect to a reference axis, when the yaw rate of the towing vehicle is null or negligible (e.g. when the towing vehicle is moving along a straight line). Consequently, when consulting the description the claim could not be strictly construed as requiring the measurement of the rate of the angle made by an axis passing through the hitch pivot point with respect to a reference axis under any conditions or movements of the towing vehicle. The claim had to be construed in a broader manner, i.e. as only requiring that said measurement could be made under certain conditions.

In T 1999/23 stellte die Kammer fest, dass die Fachperson unter dem Begriff "Anregungsfläche" (in Merkmal M1.7) für sich genommen die Querschnittsfläche des Anregungslichts auf der Probe verstehen würde – unabhängig von der Entfernung zwischen Probe und fotothermischem Gerät. Allerdings wurde dieser für die Fachperson klare Begriff in Absatz [0008] der Beschreibung des Streitpatents in einschränkender Weise definiert: "Der Begriff 'Anregungsfläche' meint die Querschnittsfläche des Anregungslichts im Fokus..

Die Kammer erläuterte, dass die Große Beschwerdekammer in G 1/24 klargestellt habe, dass bei der Auslegung von Patentansprüchen die Beschreibung heranzuziehen sei, im Übrigen aber auf die durch die Rechtsprechung entwickelten Grundsätze verwiesen habe. Einer dieser Grundsätze laute, dass eine einschränkende Begriffsdefinition in der Beschreibung nicht dazu verwendet werden dürfe, den ansonsten für die Fachperson eindeutig breiteren Anspruchsgegenstand einzuschränken (siehe Rechtsprechung der Beschwerdekammern, 10. Aufl. 2022, II.A.6.3.4). Dieser Grundsatz behalte auch nach der Entscheidung G 1/24 Gültigkeit, da die Große Beschwerdekammer betont habe, dass die Auslegung bei den Patentansprüchen beginnt und auf ihnen beruht.

Im vorliegenden Fall habe die Patentinhaberin durch die inkonsistente Verwendung des Begriffs "Anregungsfläche" – einerseits im Anspruch ohne Einschränkung, andererseits in der Beschreibung mit fachunüblicher Einschränkung – eine Zweideutigkeit geschaffen..

Die Kammer sah keinen sachlichen Grund, weshalb es einem Patentinhaber gestattet sein sollte, bei der Formulierung des Gegenstands, von dessen Nutzung Dritte ausgeschlossen werden sollen, von der fachlich etablierten Terminologie ohne erkennbare Rechtfertigung abzuweichen und hierauf nur in der Beschreibung hinzuweisen. Ein uneingeschränktes Recht hierzu würde die Rechtssicherheit untergraben. Zwar möge es im Einzelfall rechtfertigende sachliche Gründe geben. Im vorliegenden Fall sei ein solcher Grund für die Kammer jedoch nicht ersichtlich.

Im Ergebnis zeige der Blick in die Beschreibung lediglich, dass in der Beschreibung eine begriffliche Abweichung von der fachüblichen Terminologie bestehe, die sich im Anspruch nicht widerspiegele. Diese Zweideutigkeit zulasten desjenigen aufzulösen, der sie ohne sachliche Notwendigkeit geschaffen habe, entspreche dem Prinzip der Rechtssicherheit sowie dem in der Entscheidung G 1/24 bekräftigten Vorrang der Patentansprüche.

Daher sei der Begriff "Anregungsfläche" im Anspruch im Sinne seiner fachüblichen Bedeutung als "Querschnittsfläche des Anregungslichtes unabhängig vom Abstand" und nicht eingeschränkt als "Querschnittsfläche des Anregungslichts im Fokus" zu verstehen.

In T 405/24 the board agreed with the opposition division and the respondents that granted claim 1 contained added subject-matter. Feature 1.7 bore no limitation in respect of the type of "filtered packets" being "routed" to the "proxy system".

The appellant argued that "routing filtered packets to a proxy system" in the context of claim 1 was to be broadly construed, i.e. it should not be narrowly interpreted as "network-layer routing" only. Rather, it should include any kind of "sending", "forwarding" or "logging". The unit "RG1" in step #19 of Fig. 3B at the very least "forwarded" to the proxy device "PD1" those packets (comprising encrypted data) which were not "dropped" but "logged". Thus, the skilled person in the field of data communications would have understood that such "forwarding" was providing a basis for the "routing" action of feature 1.7. According to the appellant, if multiple technically sensible interpretations of a certain claim feature existed, the one which was supported by the patent description should prevail.

The board was not persuaded by the appellant’s argument. First, the board considered that even if the Order of G 1/24 (which related to assessing compliance with Art. 52 to 57 EPC only) could be extrapolated to the assessment of compliance with Art. 123(2) EPC, there was no indication in G 1/24 that "consulting" or "referring to" the description and drawings could translate into adopting a claim interpretation which ensured that the disputed feature was originally disclosed and thus necessarily fulfilled Art. 123(2) EPC. Such an approach, which according to the board inherently assumed 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 assessment of compliance with Art. 123(2) EPC. The board did not follow the approach of T 367/20 (for the event of "mutually exclusive" interpretations) nor T 2048/22 (claim ambiguities). Rather, the board relied on the body of case law which holds that all technically reasonable interpretations of a disputed claim feature are to be taken into account when assessing compliance with Art. 123(2) EPC (see e.g. T 945/20, T 470/21, T 2034/21, T 193/22).

Second, even if, for the sake of argument, the "forwarding" of logged packets (comprising encrypted data) to the proxy device "PD1" in step #19 constituted a specific instance of the more general "routing filtered packets to a proxy system", this would still fail to justify the claimed generalisation, which also encompassed, among other things, network-layer routing of filtered packets not being necessarily logged.

Thus, the board concluded that the ground for opposition under Art. 100(c) EPC in conjunction with Art. 123(2) EPC prejudiced the maintenance of the patent as granted. The same objections applied to auxiliary requests 1 to 7 and 9 to 15. Auxiliary requests 8 and 2b were not admitted into the appeal proceedings. Since there were no allowable claim requests on file, the appeal was dismissed.

In T 2027/23 the board identified three major takeaways from G 1/24.

First, the wording of the claims forms the "basis" for their interpretation and the description and the drawings should always be "consulted" or "referred to". However, G 1/24 is silent as to the very purpose of such "consultation" or "reference". In particular, it cannot be inferred from G 1/24 whether the description and the drawings should be "consulted" for the purpose of, for example, deriving "explanatory aids" to claim interpretation (see e.g. UPC_CoA_335/2023, second headnote), confirming the ordinary meaning of a claim feature, determining the function or the purpose of a claim feature, or simply defining the technically skilled reader of a claim (see e.g. T 1924/20).

Second, discrepancies in claim interpretation practice between national courts, the UPC and the Boards of Appeal are undesirable and should thus be avoided.

Third, it is up to a patentee to remedy discrepancies between the description and the claims. In other words, patentees are the masters of their fate.

Moreover, the board stated that it found no authority for interpreting a claim more narrowly than the wording of the claim as understood by the person skilled in the art would allow, and that this was for several reasons.

(a) First, because "consulting the description" did not imply any specific result of such consultation: A consultation of two conflicting authorities did not a priori determine who is master. Decision G 1/24 did not require the boards to give the description preference over the wording of the claim. To the contrary, according to the Order of G 1/24, "the claims are the starting point and the basis for assessing the patentability of an invention", and as the present board added, in line with UPC_CoA_335/2023, second headnote, the claims are the "decisive basis".

(b) Second, such interpretation would contradict the well-established jurisprudence of the Boards of Appeal, which was essentially confirmed in decision G 1/24 (see e.g. also T 1999/23).

(c) Third, such an interpretation would directly contradict the second takeaway from decision G 1/24, namely a harmonised claim interpretation between national courts or the UPC and the Boards of Appeal..

The board referred to decisions from the UPC and the German Federal Court of Justice and concluded that to align the judicial practice of the Boards of Appeal with that of the national courts and the UPC, 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. In cases of discrepancy between the claim language and the description, it falls upon the patentee to remedy this incongruence by amending the claim. It is not the task of the Boards of Appeal to reach such alignment by way of interpretative somersaults.

In the present case, the board "consulted" the description and drawings to define the technically skilled reader from whose perspective the claim features (d) to (f) were to be interpreted.

In T 1193/23 hatte die Beschwerdegegnerin (Patentinhaberin) zu verschiedenen im Anspruch 1 des Hauptantrags verwendeten Begriffen, insbesondere "Lageregelung" sowie "überprüfen" im Vergleich zu "überwachen", Bezug auf Antworten des Chatbot ChatGPT genommen..

Die Kammer merkte an, dass die Antwort von ChatGPT an sich irrelevant war, da es bei der Auslegung des Anspruchs um das Verständnis der Fachperson geht (s. auch T 206/22). Allein die allgemein zunehmende Verbreitung und Nutzung von Chatbots, die auf Sprachmodellen ("large language models") und/oder "künstlicher Intelligenz" beruhen, rechtfertigt noch nicht die Annahme, dass eine erhaltene Antwort – die auf dem Nutzer unbekannten Trainingsdaten beruhen und zudem empfindlich vom Kontext und der genauen Formulierung der Frage(n) abhängen kann – notwendigerweise das Verständnis der Fachperson auf dem jeweiligen technischen Gebiet (zum relevanten Zeitpunkt) richtig abbildet. Der Nachweis, wie bestimmte Begriffe im Anspruch eines Patents (oder einer Patentanmeldung) durch die Fachperson ausgelegt werden, kann zum Beispiel durch geeignete Fachliteratur belegt werden. Für die behaupteten unterschiedlichen Bedeutungen der oben genannten Begriffe im relevanten technischen Gebiet war kein derartiger Nachweis eingereicht worden.

Die Kammer prüfte die anderen Argumente der Parteien und kam zu dem Schluss, dass die strittigen Merkmale in einem breiteren Sinne von der Fachperson verstanden werden, als die Beschwerdegegnerin argumentiert hatte. Da sämtliche Merkmale des Anspruchs 1 des Hauptantrags in D3 offenbart worden waren, entschied die Kammer, dass sein Gegenstand nicht neu war.

In T 417/24 claim 1 was directed to a content editing method performed by a terminal. The terminal displayed an editable user interface which displayed multimedia and doodle content. The editable user interface comprised a "content editing area" which was used to add or edit the content. The terminal displayed the added or edited content in the content editing area in response to an operation of adding or editing the content. When the terminal detected that the added content reached or exceeded a preset position in the content editing area, it automatically extended the "content editing area" by a preset size.

In the board's view, the skilled person reading claim 1 on its own, i.e. without consulting the description or drawings, understood that the "content editing area" was a specific area within the displayed editable user interface. In this area, the multimedia and doodle content was displayed, and by interacting with this area, the user could add or edit the content. With this interpretation, automatically extending the content editing area by a preset size meant extending the size of the area that the content editing area took up within the displayed user interface, for example by reducing the size of other parts of the user interface or by resizing the window in which the editable user interface was displayed.

However, from Figures 8A and 8B and their description, according to the board, the skilled person understood that, at least in one embodiment of the claimed invention, the "content editing area" was not a specific area of the displayed editable user interface within which the content was displayed and with which the user interacted to add and edit content but instead referred to the scrollable content of such an area.

The board concluded that, since the claims are to be interpreted in the light of the description and drawings (see T 2766/17, T 3097/19 and T 367/20), the scope of the term "content editing area", on its proper interpretation, encompassed the "content editing area" of the embodiment disclosed in Figures 8A and 8B and their description. It followed that the meaning of the term "content editing area" deviated substantially from the meaning which the skilled person would ascribe to it based solely on the wording of the claim alone. Claim 1 therefore failed to meet the requirement of Art. 84 EPC that, as far as possible, the meaning of the terms of the claims be clear from their wording alone (G 1/04, OJ 2006, 334, point 6.2 of the Reasons; T 3097/19).

The appellant (applicant) argued that there was no contradiction between the expression "the editable user interface comprises a content editing area" in claim 1 and the disclosure in Figures 8A and 8B and their description. The application disclosed that there could be an "extended content editing area" which comprised the "content editing area" and an extension area of the content editing area. In Figures 8A and 8B, the "content editing area" was not necessarily the full document being edited (or the "scrollable content", to use the board's wording) but could be one of several regions shown in these figures.

However, the board held that Figures 8A and 8B and their description left no doubt that the content editing area 801 was indeed the whole scrollable content shown in Figure 8B, only a portion of which was visible within the area 810 of the user interface shown in Figure 8A. The appellant's argument was therefore not convincing.

In T 2651/22 the patent related to impedance matched microwave quantum circuit systems, in particular to a system comprising a parametric amplifier for amplifying a qubit readout. The interpretation of the feature "impedance matching circuit" in claim 1 was relevant to assess inventive step.

The respondent (patent proprietor) submitted that the claim could not be interpreted as covering a single integrated circuit. Feature 1.3 defined a quantum circuit device. Feature 1.4 defined an impedance matching circuit coupled to the quantum device. For the person skilled in the art it was clear that these were two different circuits. The scope of protection did not extend to one integrated circuit with double functionality as that of D8. Had the patentee desired to cover such a circuit it would have worded the claim differently, for instance to define an impedance matched circuit, not an impedance matching circuit. The specification was also consistent in describing two different circuits (figures 5, 6, 8A and 8B), one of which being placed in front of the amplifier and providing only impedance matching functionality and no amplification.

The appellant (opponent) argued that the patentee's intention when drafting the claim was irrelevant. If the claimed technical features could be mapped to the prior art then that was sufficient for the features to be disclosed. In order to establish a difference vis-à-vis D8 the claim should have been limited by inserting features from the specification into the claim, instead of relying on the specification for interpretation.

The board found the position of both parties to be reasoned and reasonable. The problem lay in the inherent difficulty of defining whether and when circuitry which is part of a larger circuitry can be identified as one circuit separate from the rest, or as fulfilling only one function. In the present case for instance, the presence of an impedance matching circuit as described in the specification also influenced the amplifying function; it improved it by reducing losses.

Considering this context, the board was of the opinion that the claim had to be interpreted in the light of the description. On that basis the board concluded that the claimed impedance matching circuit was to be interpreted as a circuit designed specifically for the (sole) purpose of impedance matching of a preexisting quantum device circuit to external circuitry.

It was undisputed that D8 did not disclose such a circuit. Further, the appellant did not argue that under this interpretation the claimed matter was obvious. Accordingly, the board came to the conclusion that claim 1 of the patent as maintained was inventive over D8.

In G 1/24 the Enlarged Board ("EBA") considered the points of law referred to it by Technical Board of Appeal 3.2.01 in T 439/22 of 24 June 2024. The first question was whether Art. 69(1), second sentence, EPC and Art. 1 of the Protocol on the Interpretation of Article 69 EPC are to be applied to the interpretation of patent claims when assessing the patentability of an invention under Art. 52 to 57 EPC. The second question concerned whether the description and figures are to be consulted when interpreting the claims to assess patentability and, if so, whether this may be done generally or only if the person skilled in the art finds a claim to be unclear or ambiguous when read in isolation. The third and final question was whether a definition or similar information on a term used in the claims, which is explicitly given in the description, can be disregarded when interpreting the claims to assess patentability and, if so, under what conditions.

The EBA confirmed that the departments of the EPO were required to interpret patent claims when assessing the patentability of an invention under Art. 52 to 57 EPC. As regards Question 1, the EBA held that there was no clear legal basis, in terms of an article of the EPC, for claim interpretation when assessing patentability. Article 69 EPC and Art. 1 of the Protocol were arguably only concerned with infringement actions and therefore were not entirely satisfactory as a basis for claim interpretation when assessing patentability. Article 84 EPC could also be criticised as an alternative legal basis as it addresses the content of the patent application and is formal in nature without providing guidance on how to interpret claims. It only sets out an instruction to the drafter of what needs to be in the claims and an instruction to the EPO to determine whether the claims meet that purpose. The EBA considered, however, that there was an existing body of case law of the Boards of Appeal which applied the wording of the aforementioned provisions in an analogous way to the examination of patentability under Art. 52 to 57 EPC, and from which the applicable principles of claim interpretation could be extracted.

The EBA further held it a settled point in the case law of the Boards of Appeal that the claims are the starting point and the basis for assessing the patentability of an invention under Art. 52 to 57 EPC.

As regards Question 2, the EBA stated that the description and any drawings must always be consulted when interpreting the claims, and not just in the case of unclarity or ambiguity. In adopting this position, the EBA rejected the case law of the Boards of Appeal that sees no need to refer to the descriptions and drawings when interpreting a claim, unless the claim is unclear or ambiguous. It found that this case law was contrary to the wording, and hence the principles, of Art. 69 EPC. It was also contrary to the practice of both the national courts of the EPC contracting states and the UPC. Moreover, from a logical point of view, the finding that the language of a claim is clear and unambiguous was an act of interpretation, not a preliminary stage to such an interpretative act.

Question 3 was held inadmissible by the EBA, which considered it to be encompassed by Question 2.

The EBA also referred to the harmonisation philosophy behind the EPC and noted that the case law of the UPC Court of Appeal on claim interpretation appeared to be consistent with the above conclusions. It further highlighted the importance of the examining division carrying out a high quality examination of whether a claim fulfils the clarity requirements of Art. 84 EPC, and stated that the correct response to any unclarity in a claim was amendment.

The order by the EBA in G 1/24 reads as follows: "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."

In T 2116/22 the interpretation of the terms "coating" and "coated" in claim 1 of the main request was relevant to assess novelty.

The appellants-patent proprietors argued that these terms had to be interpreted taking into account the whole patent. The skilled person would have understood the coating step and the thrombin-coated gelatin granules defined in the claims as being limited respectively to a process as specified in paragraph [0014] of the patent and to thrombin coated gelatin granules prepared thereby.

The board observed that the wording of the claim did not restrict the coating step to the specific coating conditions mentioned in paragraph [0014] of the patent. While the limitation of the final product being a "dry and stable" hemostatic composition may imply some limitations on the process steps, these encompassed any process features resulting in a dry and stable product such as indeed the ones described in paragraph [0014] of the patent but also any other process features providing a dry and stable product. The board further noted that the term "coating" or "coated" had a clear meaning in the field of pharmaceutical preparations and corresponded to the application of a material to the surface of a pharmaceutical solid product. This was usually done by applying the coating material as a solution or suspension to the pharmaceutical solid product and evaporating the vehicle. Paragraph [0014] of the patent did not provide a different definition of the term "coating" or "coated" than the one commonly accepted in the art. The description provided first a description of the process in broad terms as in claim 1 before describing more specific embodiments and preferred features, such as in paragraph [0014]. Whether read alone or in the light of the entire description, the meaning of the coating step or the coated product remained the same.

In the context of the discussion regarding the interpretation of the terms "coating" and "coated", the appellants-patent proprietors had requested that the board stay the proceedings in view of the pending referral G 1/24.

The board stated that the provisions in the EPC concerning a stay of proceedings following a referral to the Enlarged Board only concerned the referring board (Art. 112(3) EPC). There was, however, no legal basis in the EPC nor in the Rules of Procedure of the Boards of Appeal requiring that any other board stay its proceedings to await the outcome of the proceedings before the Enlarged Board. The decision whether or not to stay the proceedings in such cases was thus a discretionary one.

According to the board, the strict approach taken in T 166/84, namely to stay the proceedings whenever the outcome of the proceedings depended entirely on the outcome of the referral, had been applied by some boards (e.g. T 426/00, T 1875/07 and T 1044/07). However, it had also been put into question for lack of a legal basis, and considered not to apply to proceedings before the Boards of Appeal (e.g. T 1473/13 and T 1870/16). The board was of the view that a strict application of the approach taken in T 166/84 would in effect deny a board its discretion as to whether to stay the proceedings. The discretion was however the inevitable consequence of the fact that there was no legal basis for requiring a board that had not referred the relevant questions to the Enlarged Board to stay the proceedings. Moreover, the outcome of the referral G 1/24 was not decisive for the decision in the case at hand.

The board decided not to stay the proceedings in view of the pending referral G 1/24 and concluded that claim 1 of the main request was not novel. During the course of the oral proceedings, the appellants-patent proprietors filed an objection under R. 106 EPC. The board reiterated that the decision to stay the proceedings remained a discretionary one. The appellants-patent proprietors had had ample opportunities to present their comments on the issue of a stay of the proceedings, so that no violation of their right to be heard occurred (Art. 113(1) EPC). Moreover, the outcome of the referral G 1/24 was not decisive for the decision in the present case, including on novelty of the main request. Therefore, the board dismissed the objection under R. 106 EPC.

In T 325/23 the board agreed with the appellant (patent proprietor) that in general there exists no file wrapper estoppel in proceedings under the EPC. A file wrapper estoppel is a concept in US patent law. It refers to the doctrine that the patent proprietor may be estopped from enforcing an interpretation of patent claims that is inconsistent with statements made during the patent prosecution process. This concept does not exist in the EPC. However, the fact that the appellant had argued during the prosecution of the patent application that the limitation "single row" added to claim 1 was made in order to limit the subject-matter of claim 1 against prior-art document D9 which disclosed "multiple rows", could be taken as an indication that a narrow interpretation of the term "single row" was at least not technically unreasonable. It was therefore appropriate, at a later stage of the proceedings, to follow such a narrow interpretation, which had even been adopted by the appellant during earlier proceedings. Such an interpretation did not correspond to a "file wrapper estoppel" because it did not limit the interpretation of a certain feature to what was argued by the then applicant for all future proceedings. Rather, the consideration of such events in the file history was used to determine whether an interpretation was technically reasonable or not, without excluding other interpretations.

The board did not agree with the appellant's assumption that once an interpretation of a feature was determined, it could only be assessed whether this interpretation contravened Art. 100(c) EPC. Other interpretations were, according to the appellant, no longer relevant for the assessment of the admissibility of amendments.

According to settled case law of the Boards of Appeal, all technically reasonable interpretations of an ambiguous claim have to be considered. If one of those interpretations contains matter that extends beyond the content of the application as originally filed, it has to be concluded that there is added subject-matter (CLB, 10th edn. 2022, II.E.1.3.9e)).

In the context of claim interpretation the appellant further argued that a non-specific definition in a claim should be given its broadest technically sensible meaning and referred inter alia to the chapters II.A.6.1 and I.C.4.1 of CLB, 10th edn. 2022. The board disagreed. While it is true that according to these two chapters a non-specific definition in a claim should be given its broadest technically sensible meaning, none of these citations refer to the interpretation of claims in the context of assessing the admissibility of amendments under Art. 100(c) EPC or Art. 123(2) EPC. The board therefore concluded that all technically reasonable interpretations of the disputed feature had to be taken into account for the assessment under Art. 100(c) EPC.

In the case in hand, the disputed feature was feature (h). The board assessed whether the (narrow) interpretation of feature (h), according to which "single row" meant a single connector line, was already encompassed by the content of the application as filed and it concluded that the ground for opposition pursuant to Art. 100(c) EPC prejudiced the maintenance of the patent as granted (main request). The same reasons applied to auxiliary requests IA and IB and I to XXIII.

In T 583/23 the parties agreed that claim 1 related to a closed composition, i.e. a smoke condensate that did not include other components than those stated in the claim.

The board noted that claim construction, namely the meaning that a skilled person would give to the wording of a claim, was a question of law. In determining this, the board was not bound by the parties' views on the matter. The smoke condensate composition defined in claim 1 was introduced by the term "comprising." Due to the open-ended nature of this formulation, the inclusion of additional ingredients was, in principle, not excluded. Moreover, the scope of claim 1 included smoke condensates having a low pH of between 2.0 and 3.5, which were a preferred embodiment in the patent. These smoke condensates must necessarily comprise acids. Likewise, claims 2 and 3 contained further limitations which were not in line with a "closed" interpretation of claim 1.

Citing T 107/14 and T 303/20, the respondent (opponent) had argued that claim 2 as granted was a "false dependent claim" because it altered the closed composition of an allegedly closed independent claim 1. The board disagreed. As suggested in T 107/14, whether a particular amendment extended beyond the content of the application as originally filed must be assessed based on the information that is clearly and unambiguously disclosed in the entire application as originally filed, i.e. on the merits of the specific case. The same holds true for the interpretation of a specific claim and the question of whether it is a dependent claim or not.

According to the board, the indication "and the rest water" in claim 1 did not rule out the presence of further components in the smoke condensates, as long as water complemented the composition to 100 wt%. Such an interpretation of claim 1 was technically not nonsensical. By contrast, it was in line with e.g. claims 2 and 3 when interpreted as "truly dependent claims", and it led to a scenario which was not at variance with the teaching of the patent itself.

For these reasons, the board construed claim 1 as encompassing smoke condensates which could comprise other components than those explicitly specified in the claim ("open claim formulation"), such as, undoubtedly, acids.