EPO Updates Case Law Of The Boards Of Appeal Book

The EPO’s latest updates highlight recent Board of Appeal decisions on prior art, claim interpretation, added subject-matter and appeal procedure

In June 2026, the EPO published updates to the 11^th edition of its Case Law of the Boards of Appeal (‘case law book’). Some notable changes are summarised below. These all relate to recent developments from the EPO Technical and Enlarged Boards of Appeal, many of which we have discussed in our articles and webinars. It is useful to know which decisions are mentioned in the case law book, as these can sometimes carry more weight in EPO proceedings.

Patentability

Products put on the market and their analysable properties (I.C.3.2.4d)

This section has been updated following the Enlarged Board’s decision in G 1/23, which deals with products placed on the market and whether they can be analysed. revises the interpretation of G 1/92. The updated sections of the case law book highlight that the expected reproducibility of the product as required in G 1/92 is to be understood in a broader sense, namely as the ability of the skilled person to obtain and possess the physical product. G 1/23 therefore interprets G 1/92 as meaning that products are part of the state of the art when the product as such is available to the public and can be analysed by the skilled person, irrespective of whether particular reasons can be identified for analysing the composition.

This section of the case law book also highlights recent decision T 807/23, in which the Board recognised that under G 1/23, it is clear that the reproducibility requirement is no longer relevant in assessing whether a product put on the market before the filing date of the opposed patent or technical information about such a product is state of the art within the meaning of Article 54(2) EPC.

Reproducibility and selecting closest prior art (I.D.3.8.1)

This section has been added in view of the recent G 1/23 decision discussed above. It clarifies that a product does not need to be reproducible by the skilled person in order to be considered prior art or selected as the closest prior art.

Patent application and amendments

Claims supported by the description (II.A.5.3)

The case law book now references the pending G 1/25 referral which deals with questions on whether amendments to the description for conformity with the claims are a legal requirement and highlights the current diverging case law on this issue. We can expect this section to be updated once the decision in G 1/25 is handed down.

Interpretation of claims (II.A.6.1 to II.A.6.3)

The main updates to this section reflect the Enlarged Board’s recent decision in G 1/24.

G 1/24 deals with questions on claim interpretation and whether the description and drawings should be taken into account when interpreting the claims. The case law book now reflects the Enlarged Board’s decision, which confirmed that the claims are the starting point for assessing patentability and that the description and drawings must always be consulted when interpreting the claims and not only where a claim appears unclear or ambiguous in isolation. Various cases dealing with the use of the description and drawings to interpret the claims have been included in the case law book.

New decisions have also been added to the case law book relating to claim interpretation, including cases that explain that claim construction omitting a technically meaningful feature did not constitute good-faith interpretation of the claim (T 837/24), applicable grammar rules must be considered (T 1382/20), and that the interpretation of terms by a chatbot, such as ChatGPT, is irrelevant since the interpretation of the claim depends on how it was understood by the skilled person (T 1193/23). The updated section also refers to a recent decision (T 325/23) which confirms that there is no file wrapper estoppel in proceedings under the EPC, but an interpretation argued by the patent proprietor during the prosecution of the patent application could be taken as an indication that said interpretation was at least not technically unreasonable.

Article 123(2) EPC – added subject-matter (II.E.1)

Several new decisions have been added to the added matter section of the case law book. These cases provide more examples of the application of the “gold standard” for added matter, namely whether an amendment is directly and unambiguously derivable from the application as filed.

Rules common to all proceedings before the EPO

Format of oral proceedings held after the end of pandemic-related measures (III.C.8.3.3)

This section has been updated to summarise the decisions on the use of videoconferencing for oral proceedings after the end of the pandemic-related measures before the Boards of Appeal. The case law book now highlights that in the majority of decisions, the Boards regard G 1/21 as providing guidance for the exercise of their discretion under Article 15a RPBA beyond a general emergency when deciding the format of oral proceedings.

Intervention in opposition and appeal proceedings and legal status of the intervener (III.P.2.4.1 and III.P.3.2)

The main update to this section is to include the Enlarged Board’s recent decision on interventions, G 2/24. This decision confirms the findings of G 3/04 that an intervener in appeal proceedings does not acquire the status of an appellant, and so proceedings cannot be continued by the intervener if all appeals are withdrawn.

The updated section on interventions in opposition proceedings also reinforces that interventions are allowed in pending opposition proceedings but do not allow the opening of new proceedings or an independent stage of the proceedings. Therefore, interveners are not allowed to intervene in matters which have already been concluded. The updated section in relation to appeal proceedings reiterates the findings in G 1/94 that an intervener may raise new grounds of opposition during appeal proceedings, provided that a final decision has not already been made on that matter.

Proceedings before the Board of Appeal

Referral under Article 112 RPBA and stay of appeal proceedings following a referral (V.B.2.3.2 and V.B.2.5.4)

This section has been updated to include reference to the recent Enlarged Board decision G 2/24. It highlights that Boards retain discretion to refer questions to the Enlarged Board, but this must not be solely because a Board disagrees with an earlier Enlarged Board decision. The updated section notes that a Board referring questions previously addressed by the Enlarged Board should explain why further clarification is required, for example because of a change in the legal framework, a gap in the previous reasoning, or a materially different factual or procedural situation. The updates in this section also emphasise that Boards have discretion when deciding whether to stay proceedings pending a referral and that a stay is not required in every case (T 1021/23 and T 2116/22).