1.4. The examination of clarity in opposition proceedings

Art. 84 EPC is not a ground for opposition. However, when substantive amendments are made to a patent during an opposition, consideration has to be given to whether the amendments introduce any contravention of any requirement of the EPC, including Art. 84 EPC (T 301/87, OJ 1990, 335). In G 3/14 (applied inter alia in T 1977/13, T 1905/13, T 565/11, T 248/13, T 1287/14, T 2311/15, T 2321/15) the Enlarged Board analysed whether, and if so to what extent, the requirements of Art. 84 EPC may be examined in opposition and opposition appeal proceedings, in particular if the amended claim is a mere combination of a granted independent claim and granted dependent claims or elements thereof. The Enlarged Board approved T 301/87 and held that, for the purposes of Art. 101(3) EPC, the claims may be examined for compliance with Art. 84 EPC only when, and then only to the extent that the amendment introduces non-compliance with Art. 84 EPC (see chapter IV.C.5.2.2 "Extent of power to examine amended claims for compliance with Article 84 EPC").