Oppositions are very useful centralized proceedings aimed at allowing third parties to obtain the revocation of any patent granted by the European Patent Office (EPO) which is held to be invalid. Oppositions can be based on the following grounds: lack of patentability, lack of novelty, lack of inventive step, lack of industrial applicability, added matter and insufficiency of disclosure. On the other hand, oppositions cannot be based on the lack of clarity of the granted claims. In fact, the requirement that the the claims shall define the matter for which protection is sought, and that they shall be clear and concise and be supported by the description, is contained in Art. 84 of the European Patent Convention (EPC), and the requirement Art. 84 is not among the list of grounds of opposition contained in the relevant EPC provisions.

The impossibility to challenge a granted patent for lack of clarity in opposition proceedings is an area of concern for many third parties. In fact, third parties often feel that their competitors are granted patents with claims that are not sufficiently clear to allow for the claims to be interpreted with a sufficient degree of certainty, so as to allow the third parties to understand what is protected by the patent and what is instead free of protection and can thus be implemented by the third party without the patentee’s authorization.

The highest instance of the EPO, i.e. the Enlarged Board of Appeal (EBA) has now issued a very important decision regarding precisely the extent to which clarity must be assessed where the claims are amended in the course of opposition proceedings.

As a first point, in its decision the EBA has confirmed that lack of clarity is not a ground of opposition; thus it cannot be raised by an opponent with respect to an unamended granted independent claim or an unamended granted dependent claim.

Furthermore, the EBA has stated that even when the claims are amended during opposition, this does not mean that the entire patent or all of the claims (including the unamended ones) can be reviewed for clarity. Rather, only the actual amendments should be reviewed for clarity.

Finally, even on the latter point the EBA decision is quite restrictive in its interpretation of the relevant EPC provisions. In fact, the headnote of the EBA decision states that:

“In considering whether …a patent as amended meets the requirements of the EPC, the claims of the patent may be examined for compliance with the requirements of Article 84 EPC only when, and then only to the extent that, the amendment introduces non-compliance with Article 84 EPC.”

As an example of amendments which according to the EBA should not be susceptible of being reviewed for clarity during opposition proceedings, the EBA cites amendments resulting from the deletion of an independent claim X and the rewriting of a dependent claim Y, depending on the deleted independent claim X, as an independent claim Z containing all the features of the deleted independent claim X and of the former dependent claim Y.

The EBA decision will surely influence pending and future opposition proceedings in all fields of technology. In fact, there is no obligation for a granted independent claim to be amended in opposition proceedings by including all features of a dependent claim. Often the amendment is instead based on only one of several feature mentioned in a dependent claim, or even on a feature taken from the description. It will be interesting to see how successfully opponents will be able to raise lack of clarity objections in the latter scenarios.


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