13 Feb 2018 | Patents and Utility Models

G 1/16 – To disclaim or not to disclaim

With the referral G1/16 to the Enlarged Board of Appeal of the EPO, legal guidance is expected as to whether a person skilled in the art, taking into account the gold standard for amendments developed in G 2/10, would also consider the subject-matter remaining after the introduction of a non-disclosed disclaimer in a claim as explicitly or implicitly, but directly and unambiguously disclosed in the application as filed.

In drafting patent applications, a challenge faced by applicants and their representatives is to define the specific invention and yet to achieve as broad a generalization as possible so as to (i) cover future modifications of the invention and (ii) prevent competitors from easily circumventing the patented teaching.

After expiry of the priority year, amendments to the disclosure extending beyond the application as filed are not permitted as ruled by Article 123 (2) EPC in proceedings before the European Patent Office (EPO). Since the EPO was in existence, many decisions have been taken by the Technical Board of Appeals (TBoA) and the EPO’s Enlarged Board of Appeal (EBoA) dealing with various types of changes.

A special type of amendment is the “non-disclosed disclaimer” that is used to exclude certain embodiments from a generically formulated claim by incorporation of a wording that is not originally disclosed in the application. Embodiments to be excluded may be derived, e.g., from European patent applications filed before the priority or filing dates of an application, but which were published after these dates (“Art. 54 (3) EPC” documents). Embodiments found in documents deemed “accidental” can also be excluded. Prior art is considered to be accidental, if it is so far removed from the technical field of the invention that a person skilled in the art would not have considered them when attempting to solve the technical problem underlying the invention. Non-disclosed disclaimers differ from “disclosed disclaimers” that are explicitly excluded by appropriate formulations present in the original application.

The EBoA, particularly in decisions G 1/03 and G 2/03 (hereinafter “G 1/03”), has dealt with the admissibility of non-disclosed disclaimers. General standards for the admissibility of amendments were last set out in decision G 2/10.

G 1/03

According to G 1/03, amendments may be made by means of non-disclosed disclaimers, e.g., to exclude embodiments found in Art. 54(3) EPC documents or in accidental disclosures. The validity of G 1/03 was often questioned after their publication, as discussed in the interlocutory decision underlying G 1/16.

G 2/10

The decision G 2/10 of the EBoA is generally recognized as a “gold standard” for the admissibility of amendments, even if the underlying case explicitly relates to the assessment of disclosed disclaimers. According to G 2/10, amendments may be permissible if the person skilled in the art had recognized the subject-matter of the amended claim as being explicit or implicit but directly and unambiguously in the application as filed, taking into account the general technical knowledge.

Compatibility of G 2/10 and G 1/03

In the interlocutory decision (T 437/14) of TBoA 3.3.09, the EBoA was presented with legal questions aimed at reviewing the compatibility of decisions G 2/10 and G 1/03. This interlocutory decision forms the basis of the referral G 1/16. The TBoA seeks guidance as to whether a person skilled in the art, taking into account the gold standard developed in G 2/10, also considered the subject-matter which remained after the introduction of a non-disclosed disclaimer in a claim as explicitly or implicitly, but directly and unambiguously disclosed in the application as filed.

T 437/14

The case on which T 437/14 is based can be summarized as follows:

  • In the disputed patent, two non-disclosed disclaimers were inserted in claim 1 due to disclosures in two prior art documents. With regard to admissibility, the patent proprietor referred to G 1/03. If the rulings adopted therein were to be applied on the admissibility of the disclaimers, this would be in the affirmative from the point of view of the referring Board.
  • According to the Board, the admissibility would, however, be negative if the standards developed in G 2/10 were used. In T 437/14, the Board argues that the application of the gold standard developed in G2/10 results in the fact that a skilled person would never, as a matter of principle, neither explicitly nor implicitly, directly and unambiguously, find the subject-matter remaining after introduction of the non-disclosed disclaimer in the application as originally filed. This interpretation of Decision G 2/10 was even confirmed by the patentee in the proceedings (reason 8.1.2).

According to reason 7.5.2 of T 437/14, the EBoA noted in G 2/10 that the exemptions under G 1/03 do not alter the general definition of the requirements of Art. 123 (2) EPC.

In reason 7.5.3, it is also noted that the EBoA in G 2/10 had responded to a proposal of the President of the EPO in the examination of the then-decided legal questions. The latter suggested that, in cases where the subject-matter of the claim cannot be directly and unambiguously deduced from the application as filed, the admissibility of the disclaimers should nevertheless be made subject to the criteria laid down in G 1/03.

However, as stated in T 437/14, the EBoA in G 2/10 did not see any justification for this approach. According to reason 7.6 of T 437/14, these observations of the EBoA in G 2/10 ultimately signify that there is only one test for the assessment of whether an amendment, including a non-disclosed disclaimer, is in accordance with Art. 123 (2) EPC, i.e. the gold standard. The decisive criterion for the admissibility of non-disclosed disclaimers is therefore as to whether the person skilled in the art, by taking into account the general technical knowledge, would consider the subject-matter remaining after introduction of the disclaimer as being explicitly or implicitly but directly and unambiguously disclosed in the application as originally filed (reason 7.7). The Board goes on to say that the standards developed by G 2/10 leave no room for the exceptions defined in G 1/03 (reason 7.8).

Finally, as the Board notes, the decision G 2/10 itself did not lead to the abolition of the exemptions made by G 1/03 after a comprehensive discussion of the latter decision and the applicability of the gold standard also to non-disclosed disclaimers.

In reason 9 of T 437/14, the case-law after the adoption of the G 2/10 is discussed. In this respect, it appeared that the Technical Boards of Appeal, in particular in the decisions T 2018/08 and T 1870/08, had developed modified interpretations of the gold standard, which require a legal review by the EBoA. In the light of this case-law, the referring Board submitted legal questions, which are likely to have fundamental significance for the future of non-disclosed disclaimers:

  • (1) Is the standard referred to in G 2/10 for the allowability of disclosed disclaimers under Art. 123 (2) EPC, i.e. whether the skilled person would, using common general knowledge, regard the subject-matter remaining in the claim after the introduction of the disclaimer as explicitly or implicitly, but directly and unambiguously, disclosed in the application as filed, also to be applied to claims containing undisclosed disclaimers?
  • (2) If the answer to the first question is yes, is G 1/03 set aside as regards the exceptions to undisclosed disclaimers defined in its answer 2.1?
  • (3) If the answer to the second question is no, i.e. if the exceptions relating to undisclosed disclaimers defined in answer 2.1 of G 1/03 apply in addition to the gold standard, may this standard be modified in view of these exceptions?

Practical significance of G 1/16

  • Applicants or proprietors who intend to include a non-disclosed disclaimer in the claims are well advised to have the procedure for the application or the patent concerned suspended until legal certainty is achieved by the rulings in G1/16.
  • Applicants should pay more attention to the fact that patent applications are designed in such a way that generic claims are described by stepwise definitions of preferred individual features resulting in additional fallback possibilities, to have a basis for amendments excluding Art. 54 (3) EPC documents or “accidental disclosures” without having to resort to non-disclosed disclaimers.
  • In cases where the exceptions listed in G 1/03 are relevant, divisional applications could be submitted, as it is not clear when and how the EBoA will decide in G 1/16.


The admissibility of amendments to patent documents remains a hot topic before the EPO. In view of the extremely strict interpretation regarding the admissibility of amendments, the importance of a well thought-out elaboration of patent documents cannot be empasized highly enough.

In this respect, it is interesting that a number of Amicus Curiae letters were submitted in the meantime, pursuant to Art. 10 of the Rules of Procedure of the EBoA. These include the epi, FICPI and the AIPPI, all of whom are in favor of maintaining the rulings in G 1/03.

Therefore, there is still the hope that respective options remain after the issuance of G 1/16.