In T 628/90 an allegation of public prior use, which was filed for the first time in appeal proceedings and was adequately substantiated, was taken into account because of its possible relevance to enable thorough consideration to be given to the patentability of the subject-matter of the contested patent (see also T 150/93, T 947/99).

In T 947/99 the appellant submitted with regard to the circumstances of the late claim concerning public prior use that he had only become aware of the possibility that there might have been public prior use in the course of proceedings conducted in parallel before the Patents Court in London at a meeting. In the board's opinion, the appellant had given a very clear explanation and sound reasons as to why the claim of public prior use had been made and why it could not have been made any earlier.

In T 571/08, the board held that documents submitted by the appellant to support a new prior use, as part of a challenge to one of a set of new auxiliary requests filed shortly before the oral proceedings before the opposition division, had not been filed belatedly. The appellant had, in response to the opposition division's decision to allow the auxiliary request with the additional feature in question, filed the documents at the earliest possible opportunity, namely with its notice of appeal.