In a recent referral to the Enlarged Board of Appeal (G 3/14) of the EPO, a series of questions has been asked regarding the extent to which claim amendments made during opposition and opposition appeal proceedings should be examined for clarity.  

The referral was made by the Board of Appeal in T 0373/12. In this case, the Opposition Division had previously revoked the European Patent No. 1 814 480 on the grounds that the claims relating to a prosthetic medical device lacked inventive step. The proprietor appealed and requested that the patent be maintained on the basis of a main request or one of thirteen auxiliary requests. In response, the opponent requested that the appeal be dismissed and further requested that the following question be submitted to the Enlarged Board of Appeal.

“Does an amendment of an independent claim during opposition proceedings hinder the examination with regard to clarity (Art. 84 EPC), if the amended claim is a combination of an independent claim as granted with the elements of a dependent claim as granted? (Contrary to the decisions T 459/09 and T 409/10)”

During EPO opposition and opposition appeal proceedings, it is common for a patentee to seek to amend the independent claim(s) of the opposed patent. There are many ways in which this can be done, but amendment usually involves combining an independent claim with elements of one or more of the dependent claims as granted in the patent, or incorporating previously “non-claimed” features from the description into an independent claim.

According to the European Patent Convention (EPC), it is not possible for a third party to oppose a granted patent on the grounds that the claims lack clarity. However, Article 101(3) EPC sets out that the Opposition Division must ensure that amendments made by the proprietor of a European patent during opposition proceedings comply with the requirements of the EPC; if they do not, the Opposition Division must revoke the patent. The same also holds true for amendments made before the Boards of Appeal. In other words, even though clarity itself is not a ground of opposition, an Opposition Division or a Board of Appeal may revoke a patent if they believe that the amended claims are unclear.

Over the last 25 years or so, the vast majority of decisions arising from the Boards of Appeal regarding this aspect of the law have held that an examination of clarity should not come into question in the situation where a granted dependent claim has been inserted in a literal fashion into an independent claim, on the premise that all granted claims have already been examined systematically by the Examination Division for clarity. 

However, the jurisprudence of the Boards of Appeal has not been uniform in this respect, as there has been divergence between decisions in recent years. For example, in T 459/09 it was held that the clarity of an amended independent claim should be examined even if it results from a literal combination of granted claims, and a similar point was made in T 409/10. In another case (T 1459/05), the Board of Appeal considered that it had the power to examine the clarity of a feature introduced in literal terms on the basis that there could no longer be an unqualified assumption that all features of the dependent claims of a granted patent had been examined systematically for clarity, due to the fact that there has been a steep rise in the number of claims contained in applications.

Since the application of the law has not been uniform, and the question of under what circumstances and to what extent an Opposition Division or a Board of Appeal are empowered, or required, to examine the clarity of claims which are amended during opposition or opposition appeal arises frequently in practice, the Board of Appeal in T 0373/12 decided that it was a point of fundamental importance, which required a decision by the Enlarged Board of Appeal. 

For completeness, the questions referred to the Enlarged Board of Appeal by the Board of Appeal in T 0373/12 are set out in full below:

  1. Is the term “amendments” as used in decision G9/91 of the Enlarged Board of Appeal (see point 3.2.1) to be understood as encompassing a literal insertion of (a) elements of dependent claims as granted and/or (b) complete dependent claims as granted into an independent claim, so that Opposition Divisions and Boards of Appeal are required by Article 101(3) EPC always to examine the clarity of independent claims thus amended during the proceedings?
  2. If the Enlarged Board of Appeal answers Question 1 in the affirmative, is then an examination of the clarity of the independent claim in such cases limited to the inserted features or may it extend to features already contained in the unamended independent claim?
  3. If the Enlarged Board answers Question 1 in the negative, is then an examination of the clarity of independent claims thus amended always excluded?
  4. If the Enlarged Board comes to the conclusion that an examination of the clarity of independent claims thus amended is neither always required nor always excluded, what then are the conditions to be applied in deciding whether an examination of clarity comes into question in a given case?

Looking forward, the referral could have an influence on how the European Patent Office examines claims of an application during prosecution. More importantly, however, the outcome of the referral could benefit opponents in that it may be possible to object to an amendment made during an opposition or opposition appeal proceedings on the basis of clarity when all other potential avenues of attack have been exhausted.