The European Patent Office's Enlarged Board of Appeal rules on when Article 84 scrutiny is permitted in opposition proceedings

8 minute read
27 March 2015

The European Patent Office's (EPO) Enlarged Board of Appeal (EBA) has ruled that in opposition proceedings, scrutiny of the claims pursuant to Article 84 EPC (clarity and support) is only permitted when, and to the extent that, the proposed amendment introduces the alleged non-compliance.

The examination of an opposition to a European patent and the revocation or maintenance of a European patent pursuant to the opposition procedure are governed by Article 101 of the European Patent Convention (EPC). Where the Opposition Division finds that a ground for opposition prejudices the maintenance of a patent, amendment may become appropriate.

However, there has been ambiguity in the EPO's case law as to the extent to which the Opposition Division should then examine the proposed amended claims for compliance with the requirements of the EPC more generally.

Background: EPC provisions

The grounds for opposing the grant of a European patent are specified in an exhaustive list in Article 100 EPC. They do not include that the patent as granted fails to meet the requirements of Article 84, which states:

"The claims shall define the matter for which protection is sought. They shall be clear and concise and supported by the claims."

The examination of the opposition is governed by EPC Article 101. Paragraph (3) states:

"If the Opposition Division is of the opinion that, taking into consideration the amendments made by the proprietor of the European patent during the opposition proceedings, the patent and the invention to which it relates

  1. meet the requirements of this Convention, it shall decide to maintain the patent as amended, provided that the conditions laid down in the Implementing Regulations are fulfilled;
  2. do not meet the requirements of this convention, it shall revoke the patent."

What does Article 101(3) EPC mean?

In decision G3/14 (Examination of clarity objections) of 24 March 2015, the EBA confirmed that when the article speaks of amendments "made" by the proprietor and whether the "patent" and the invention to which it relates meet the requirements of the EPC, what is referred to is the proposed amendment(s) to the patent, particularly the claims, put forward by the proprietor as part of a request to maintain the patent in amended form. The issue is then whether such a request (assuming it is admissible) is allowable having regard to the provisions of Article 101(3).

But what does "meet the requirements of this invention mean"? Does it require a full examination of the compliance of the proposed amended claim with all the requirements of the EPC, including provisions such as Article 84? (Remember, Article 84 is not contained within the exhaustive list of grounds for opposition.)

The EBA stated that it "sees no reason to doubt that the requirements of Article 84 EPC are also part of the requirements of the Convention for the purposes of Article 101(3)". This is because the words "meet the requirements of this Convention" are the same as those used in Articles 94 (Examination) and 97 EPC (Grant or refusal); and the requirements of Art 84 are part of the requirements of the EPC for the purposes of Articles 94 and 97. The effects of Article 84 EPC therefore do not come to an end with the grant of the patent.

However, while it is not optimal that there may be granted claims, even after amendment, which do not comply with Article 84 EPC, the EBA explained that the legislator has deliberately chosen not to make Article 84 EPC a ground for opposition, or for revocation or nullity in national proceedings.

Lack of clarity may have a 'profound' effect on the outcome of challenges of insufficiency, anticipation or obviousness, but opposition proceedings are not designed to be a continuation of examination proceedings. A finding that a ground for opposition prejudices the maintenance of a patent, so that amendment becomes appropriate, does not open a door to scrutinise the patent thoroughly for compliance with all requirements of the EPC.

Therefore, following grant (i.e. in the course of an opposition or limitation procedure), proposed amended claims may be examined for compliance with the requirements of Article 84 only when, and then only to the extent that, the amendment introduces non-compliance with Article 84 EPC.

The EBA considered this approach to be in line with the earlier conclusions which had been reached about the interpretation of Article 101(3), having regard to G 9/91 and G 10/91, the context of the article and the object and purpose of the EPC and the travaux préparatoires.

The EBA explained that the principle applies consistently for different types of claim amendment:

  1. 'Type B': a literal insertion of a complete dependent claim as granted into an independent claim. (For example, Granted claim 1: a product comprising X; granted claim 2, a product according to claim 1 wherein the amount of X comprised in the product is substantial; amended claim 1: a product comprising a substantial amount of X). In reality this consists of striking out the original independent claim and then writing out the previous dependent claim in full. While the patent must be considered to have been amended, the claim which is in place after the amendment is in reality and substance not a new claim. It was already in the granted patent.
  2. 'Type A(i)': cases where a dependent claim contains within it alternative embodiments (perhaps with one or more of them being preferred), one of which is then combined with its independent claim. (For example, granted claim 1, a product comprising X; granted claim 2, a product according to claim 1, comprising also a substantial amount of either Y or [preferably] Z, the amended claim then being to a product comprising X and also a substantial amount of Z). The granted dependent claim could (but for the requirement of conciseness) have been written out as two (or more) separate dependent claims. Such cases are in substance no different to Type B amendments.
  3. Amendments consisting of deletion of wording from a granted claim, thereby narrowing its scope, but leaving intact a pre-existing lack of compliance with Article 84. Again, the same applies.
  4. Deletion of optional features from a granted claim. Again, the same applies.
  5. 'Type A(ii)': Cases where a feature is introduced into an independent claim from a dependent claim, being a feature which was previously connected with other features of that dependent claim from which it is now disconnected. It has never been doubted that where an alleged lack of compliance is introduced by such an amendment, the claim may be examined for such compliance. However, where the alleged lack of compliance has not been introduced by the amendment, such cases are in substance no different to Type B.

The EBA thus approved the 'conventional' line of jurisprudence as exemplified by decision T 301/87 and disapproved the line of jurisprudence as exemplified by decision T 472/88.


The EBA's ruling on the interpretation of Art 101(3) EPC, specifically on the extent to which Article 84 may be considered in the context of considering whether to permit amended claims post grant, provides welcome clarity as to the scope of claim 'examination' in the course of post-grant amendment proceedings.

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