Undisclosed disclaimers in Europe – regulations reloaded

This is an Insight article, written by a selected partner as part of IAM's co-published content. Read more on Insight

In most cases, during the examination of a patent application before grant or during opposition proceedings of a patent after grant, the applicant must deal with prior art documents cited by the examiner or opponents against the patentability of the claims. Amending the application or patent – particularly by amending claims by limiting their scope – is an appropriate way to exclude embodiments of the invention that are disclosed in the prior art.

Admissibility of amendments

Whether an amendment is admissible must be decided by the competent body of the patent office. The decision is usually based on whether the amendment is supported by the application documents as filed (ie, whether the amendment introduces new matter). Amendments that are not supported in this way or that introduce new matter are generally inadmissible.

The admissibility of amendments is regulated differently in different jurisdictions. The European Patent Office (EPO) takes a relatively strict position. For patent applications examined by the EPO, Article 123(2) of the European Patent Convention (EPC) specifies that “the European patent application or European patent may not be amended in such a way that it contains subject-matter which extends beyond the content of the application as filed”. Thus, new matter is subject matter that extends beyond the content of the application as filed. The EPO Guidelines for Examination, Chapter H-IV, 2.1 state that “an amendment should be regarded as introducing subject-matter which extends beyond the content of the application as filed, and therefore unallowable, if the overall change in the content of the application (whether by way of addition, alteration or excision) results in the skilled person being presented with information which is not directly and unambiguously derivable from that previously presented by the application, even when account is taken of matter which is implicit to a person skilled in the art (see G2/10)”.

This is the gold standard for assessing subject matter added by the EPO, which was established in Decisions G3/98 and G11/91 of the Enlarged Board of Appeal.

Subject matter

The stipulations of Article 123(2) of the EPC are to prevent an applicant from improving his or her position by adding subject matter not disclosed in the application as filed. This could give the applicant an unwarranted advantage and could be damaging to the legal security of third parties relying on the content of the original application (see G1/93). The EPO therefore interprets the term ‘directly and unambiguously derivable from’ very strictly when examining the admissibility of amendments. ‘Directly and unambiguously derivable from’ means that there must be a clear basis for the amendment in the specification, claims or drawings as filed. In practice, problems arise in particular when the claims of a patent application are amended with the introduction of a disclaimer (ie, a negative feature).

The subject matter of a claim is normally defined in terms of positive features indicating that certain technical elements are present for which protection is sought. These technical features define the elements and characteristics of the claimed subject matter. However, exceptionally the subject matter may be restricted using a negative limitation expressly stating that particular features are not part of the claimed scope. Accordingly, negative features describe elements and characteristics that the claimed subject matter does not have. This may be done, for example, if the absence of a feature finds a basis in the application as filed (see T278/88). But how does the EPO deal with disclaimers in cases where there is no basis in the application as filed for the intended absence of a specific feature (ie, for the feature to be excluded)? Do these so-called ‘undisclosed disclaimers’ violate Article 123(2) and therefore become generally inadmissible?


On December 18 2017 the EPO Enlarged Board of Appeal (EBA) released the decision Disclaimer III in Case G1/16. This decision was based on referral of a Technical Board of Appeal in Decision T 437/14 (the Official Journal (OJ) EPO 2017, A50) concerning the proper standard to be applied for examining a claim amendment by the introduction of an undisclosed disclaimer. The questions resulted from case law differently interpreting the relation between Decisions G1/03 and G2/03 (OJ EPO 2004, 413 and 448) on undisclosed disclaimers on the one hand and G2/10 (OJ EPO 2012, 376) on disclosed disclaimers on the other.

In the reasoning for G1/16, the EBA analysed its earlier decisions in G1/03 and G2/10. Herein, a “disclaimer is defined as the incorporation of a negative technical feature, typically excluding specific embodiments or areas from a generally defined subject-matter”. However:

a disclaimer is only a proper disclaimer if the remaining legal subject-matter is less than that of the unamended claim. If any subject-matter can be identified which falls within the scope of the claim after amendment by the proposed disclaimer, but which did not do so before the amendment, the disclaimer is improper and, as a consequence of this, unallowable under Article 123(2) EPC. The term undisclosed disclaimer relates to the situation in which neither the disclaimer itself nor the subject-matter excluded by it have been disclosed in the application as filed. A disclosed disclaimer either introduces an originally disclosed negative feature or the exclusion of the subject-matter has a basis in the original application, eg, in a specific embodiment. (see Sections 14 to 16 of G1/16.)

Technical Boards of Appeal decisions

Three decisions of the Technical Boards of Appeal formed the basis for allowing disclaimers prior to G1/03 for several years: T4/80 (OJ EPO 1982, 149); T 433/86 (not published in the OJ EPO); and T 170/87 (OJ EPO 1989, 441).

T4/80 was the first decision to allow a disclosed disclaimer. The disclaimer was used to eliminate subject matter from the claims which was disclosed in an earlier national patent application and was not published as of the date of filing the examined European patent application. The disclaimer was allowed because the subject matter remaining in the claim could be defined no more clearly or concisely (ie, by positive technical features (Article 84 of the EPC)).

Decision T433/86 referred to Decision T4/80 and for the first time allowed an undisclosed disclaimer. A specific piece of prior art could be excluded even in the absence of support for the excluded matter in the original documents. The claim had to be delimited in order to restore novelty – it recited a molecular weight range, which was restricted to 1,500 to 10,000 (from the original range of 600 to 10,000). The restriction was necessary to distinguish the claimed subject matter from a prior art document in which a molecular weight range of between 240 and 1,500 had been disclosed. The amendment was allowed.

Decision T170/87 referred to Decisions T4/80 and T433/86 and generalised the admissibility of undisclosed disclaimers (Reasons, point 8.4.3):

The inventive teaching originally specifically disclosed in the application is not changed as a whole merely by delimiting it with respect to the state of the art or with respect to what has proved not to be functional; rather through the disclaimer (or through a ‘positive’ wording leading to the same result), only the part of the teaching which the applicant cannot claim owing to lack of novelty or reproducibility is ‘excised’ in the sense of a partial disclaimer. A considerable practical need for this exists. All that is necessary is to define appropriately what under the given circumstances is left of the inventive teaching originally disclosed that is still capable of being protected.

Several Technical Boards of Appeal decisions have further developed principles in case law and disclaimers have been allowed if the subject matter remaining in the claim after the introduction of the disclaimer could not be more clearly and concisely technically defined (ie, positively) in order to exclude accidentally novelty-destroying prior art where the disclaimer had been necessary to restore the novelty of a European patent application not yet published on the filing date of the examined European patent application (eg, ‘elder right’ under Article 54(3) of the EPC) or where the disclaimer was used to exclude non-functioning subject matter from the claims. Undisclosed disclaimers were often assessed in the same way as disclosed disclaimers. Sometimes, clarity and conciseness were used as limitations on the allowability of disclaimers. The introduction of a disclaimer should have no bearing on the other patentability requirements, particularly on the assessment of inventive step. Moreover, a disclaimer should exclude no more than necessary and does not necessarily have to be the literal wording of the excluded prior art.

However, this view of established case law was questioned in Decision T323/97 (OJ EPO 2002, 476), in which the gold standard for amendments of a European patent application or a European patent as described supra was applied on disclaimers. This meant – as far as the requirements of Article 123(2) were concerned – that the amended claim required support in the application as filed, which was mandatory for the allowability of the amended patent or patent application as explained in G3/89 (Point 2.2).

EBA questions

This deviation in the case law led to the referrals in Decisions T507/99 and T451/99 and to Decisions G1/03 and G2/03. G1/03 specifically dealt with the admissibility of undisclosed disclaimers, and the questions referred to the EBA were answered as follows:

  • An amendment to a claim by the introduction of a disclaimer may not be refused under Article 123(2) for the sole reason that neither the disclaimer nor the subject matter excluded by it from the scope of the claim have a basis in the application as filed.
  • The following criteria are to be applied for assessing the allowability of a disclaimer which is not disclosed in the application as filed:
    • a disclaimer may be allowable in order to:
      • restore novelty by delimiting a claim against state of the art under Article 54(3) and (4) of the EPC;
      • restore novelty by delimiting a claim against an accidental anticipation under Article 54(2) of the EPC – an anticipation is accidental if it is unrelated to and remote from the claimed invention that the person skilled in the art would never have taken it into consideration when making the invention; and
      • disclaim subject matter which, under Articles 52 to 57 of the EPC, is excluded from patentability for non-technical reasons;
    • a disclaimer should not remove more than is necessary either to restore novelty or disclaim subject matter excluded from patentability for non-technical reasons;
    • a disclaimer which is or becomes relevant for the assessment of inventive step or sufficiency of disclosure adds subject matter contrary to Article 123(2) of the EPC; and
    • a claim containing a disclaimer must meet the requirements of clarity and conciseness of Article 84 of the EPC.

In a second decision, the EBA ruled in G2/10 that disclaimers must conform to the gold standard for assessing added matter. G2/10 seemed to be in conflict with G1/03, specifically regarding undisclosed disclaimers which could never meet the requirements of Article 123(2) because they naturally cannot have a basis in the application documents as filed.

The new and most recent decision, G1/16 (December 2017), has settled this apparent conflict by clarifying that the gold standard does not apply to undisclosed disclaimers that meet the requirements of G1/03. In contrast, the gold standard is the relevant disclosure test for assessing the allowability of a claim amendment by the introduction of a disclosed disclaimer.

For the purpose of considering whether a claim amended by the introduction of an undisclosed disclaimer is allowable under Article 123(2), the disclaimer must fulfil one of the criteria set out in Point 2.1 of G1/03.

The introduction of such a disclaimer may not provide a technical contribution to the subject matter disclosed in the application as filed. In particular, it may not be or become relevant for the assessment of inventive step or for the question of sufficiency of disclosure. The disclaimer may not remove more than necessary, either to restore novelty or disclaim subject matter excluded from patentability for non-technical reasons.

Comment and practical implications

G1/16 has now clarified that for examining the allowability of an undisclosed disclaimer for compliance with Article 123(2), it is not the gold standard but the test based on G1/03 that is to be applied. Thus, an undisclosed disclaimer is admissible under the following prerequisites:

  • The disclaimer is introduced to:
    • restore novelty over a conflicting application within the meaning of Article 54(3) of the EPC;
    • restore novelty over an accidental anticipation; or
    • disclaim subject matter which is excluded from patentability for non-technical reasons (in particular and under specific constraints: discoveries; scientific theories; mathematical methods; aesthetic creations, schemes, rules and methods for performing mental acts, playing games or doing business; computer programs; presentations of information; inventions, the commercial exploitation of which would be contrary to ordre public or morality; plant or animal varieties or essentially biological processes for the production of plants or animals; methods for treatment of the human or animal body by surgery or therapy and diagnostic methods practised on the human or animal body); and
  • The disclaimer is not related to the teaching of the invention.

In regard to the latter, in practice this means that the evaluation of inventive step must be carried out disregarding the undisclosed disclaimer.

The EBA further clarified in G1/16 that the ‘gold standard’ defined in G2/10 remains the relevant disclosure test for assessing the allowability of a claim amendment by the introduction of a disclosed disclaimer (Reasons, Point 51). By basing the assessment to be made on the technical teaching of the original application, as already stated in G1/03, the decision resolves the alleged conflict between G1/03 and G2/10.

Maikowski & Ninnemann Patentanwälte Partnerschaft mbB

Kurfürstendamm 54-55

Berlin 10707


Tel +49 30 881 81 81

Fax +49 30 882 58 23

Web www.maikowski-ninnemann.com

Matthias Hoffmann
[email protected]

Matthias Hoffmann, a graduate biologist, has gathered long-term industry experience heading the patent department of Probiodrug AG. He is a partner in the Leipzig office and specialises in securing patent protection for chemical, pharmaceutical and biotechnology-related inventions. This includes providing strategic advice during patent prosecution and following patent grant for both pharmaceuticals and biologics. Mr Hoffmann is often called on to advise innovative pharmaceutical and biopharmaceutical companies in matters relating to data protection, licensing activities and due diligence examinations. He is a qualified patent, trademark and design attorney and has been assisting clients with securing and defending patent protection for their innovations for more than 15 years.

Fabian Sokolowski
[email protected]

Fabian Sokolowski, a graduate biochemist, has been crazy about IP counselling at Maikowski & Ninnemann since 2005. He is a partner in the Berlin office, where he is responsible for leading the life sciences practice group. His practice focuses on patent and trademark prosecution and litigation. He counsels pharmaceutical innovators and research institutions on all aspects of patent rights, including in small molecules and biologics inventions. Dr Sokolowski has significant experience in representing clients in opposition proceedings and before the Federal Patent Court, the European Patent Office and the German Patent and Trademark Office.

Unlock unlimited access to all IAM content