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Disclaimers are negative claim features that exclude specific subject matter from the scope of a claim. It is rare that a patent specification will contain specific support for omitting a feature, and hence there are generally two types of disclaimer in European practice:

  1. Undisclosed disclaimer – disclaimed features are not disclosed in original application.
  2. Disclosed disclaimer – disclaimed features are disclosed as an embodiment of the invention.

EPO decision G1/03 sets out a limited number of circumstances in which undisclosed disclaimers can be permitted, whilst the later G2/10 decision provides guidelines on determining whether a disclosed disclaimer should be considered allowable. Nevertheless, it would appear that these two rather distinct decisions are being mixed in current practice.


In T1870/08, a decision of the EPO Technical Boards of Appeal, published in March 2012, an undisclosed disclaimer was used in claim 1 to exclude the use of a particular type of oxide superconductor. The disclaimer was introduced in order to establish novelty over a prior art claim with an earlier priority date, but a later publication date, than the priority date of the patent in question. G1/03 allows the use of an undisclosed disclaimer under such circumstances if the answer to all of the following three questions is ‘no’:

  1. Does the disclaimer remove more than is necessary?
  2. Does the disclaimer become relevant for assessing inventive step and/or sufficiency?
  3. Does the declaimer contradict the requirements of Article 84 EPC (i.e., is the scope of the protection of the claim still clearly defined)?

In T1870/08, all three of these questions could be answered with ‘no’, and hence the disclaimer was considered allowable in light of G1/03.

The opponent, however, argued that the disclaimer introduced subject matter which extended beyond the content of the application as filed and hence contravened Article 123(2) EPC. The opponent argued that the correct test would be that of G2/10. Initially the Board stated that G2/10 referred to disclosed disclaimers and might not therefore be relevant in assessing the validity of undisclosed disclaimers. Nevertheless, the Board examined the claim containing the disclaimer in light of G2/10, and found that the subject matter remaining in the claim after the amendment – not the undisclosed disclaimer itself – would need to be examined for its compatibility with Article 123(2) EPC.

Since the subject matter remaining within the claim was adequately disclosed in the application as filed, and the disclaimer did not modify the technical subject matter, the amendment introducing the disclaimer into claim 1 was considered to comply with the requirements of Article 123(2) EPC, and was therefore allowable in light of both G1/03 and G2/10.


In T2464/10, three undisclosed disclaimers excluding subject matter not eligible for patent protection were allowed under G1/03. These disclaimers specifically referred to genetic modification of the germ line of a human being, and were therefore introduced to accommodate statutory prohibitions.

In accordance with G1/03, the disclaimers were found to not remove more than was necessary and to meet the requirements of Article 84 EPC, without becoming relevant for examining inventive step or sufficiency.

Further, the board followed the test set out in G2/10, deciding that:

  • “The test to be applied is whether the skilled person would, using common general knowledge, regard the remaining claimed subject matter as explicitly or implicitly, but directly and unambiguously, disclosed in the application as filed”.

This test was also satisfied and hence the disclaimers were allowed.


It may be argued that G1/03 and G2/10 should not be mixed, because they address different situations, i.e. undisclosed vs disclosed disclaimers. Recent case law from the EPO, however, suggests combining these decisions is representative of current practice.

From a conservative viewpoint, allowing undisclosed disclaimers should unequivocally add matter under Article 123(2). Nevertheless, it would appear that current practice only regards the technical subject matter remaining in the claim as relevant for examining added matter, providing the undisclosed disclaimer follows decisions G1/03 and G2/10.

Our articles are for general information only. They should not be considered specific legal advice, which is available upon request. All information in our articles is considered to be accurate at the date of publishing.


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