Under R. 99(1)(b) EPC, the notice of appeal shall contain an indication of the decision impugned.
According to J 16/94, (OJ 1997, 331), for a notice of appeal to comply with Art. 108, first sentence, EPC 1973 and R. 64(b) EPC 1973, it had to express the definite intention to contest an appealable decision. An appeal filed as a subsidiary request, i.e. conditional on the main request not being allowed by the department of first instance, was therefore inadmissible. This was because there should be legal certainty as to whether or not a decision was contested. This was confirmed by T 460/95 date: 1997-10-20 (OJ 1998, 588).
Source: http://www.epo.org/law-practice/legal-texts/html/caselaw/2019/e/clr_v_a_2_5_2_b.htm
Date retrieved: 17 May 2021