T 0328/87 (Admissibility) of 04.04.1991

1. When an opposition is based on grounds of prior use, the requirements of Rule 55(c) EPC are only fulfilled if the notice of opposition indicates, within the opposition period, all the facts which make it possible to determine the date of prior use, what has been used, and the circumstances relating to the alleged use. The notice of opposition must also indicate the evidence and arguments presented in support of the grounds of opposition. However, Rule 55(c) EPC does not stipulate that the said facts, evidence and arguments hae to be placed on file during the opposition period.

2. When an opposition has been declared inadmissible, its substance cannot be examined, nor is it possible for the EPO to examine the facts of its own motion in accordance with Article 114(1) EPC.