j) New document originating from the patent proprietor submitted by the appellant-opponent – not admitted 

In T 533/17 the appellant (opponent) argued that a poster (D19) and two related documents, filed after its grounds of appeal, should be considered since the respondent (patent proprietor) had apparently concealed this earlier own publication. The board, however, noted that R. 42(1)(b) EPC did not put a stringent obligation on applicants to acknowledge prior art known to them at the time of filing their application. Therefore, the failure to acknowledge D19 in the patent in suit was not a sufficient reason for admitting this document into the appeal proceedings. Moreover, the appellant had not provided a convincing justification of why it had not been possible to find D19 when preparing this case at the opposition stage. The new documents were therefore not considered, in accordance with Art. 13(1) and 25(3) RPBA 2020.