In the following cases, the boards found that there was an (implicit) obligation to maintain secrecy:
In T 1085/92 the board took the view that, where contractual relations and development agreements existed, a secrecy agreement could be assumed to exist.
In T 838/97 the board held that an agreement which ruled out availability to the public did not necessarily have to be a contract made in writing, as an implicit or implied agreement could also be taken into account (see e.g. T 818/93).
In T 830/90 (OJ 1994, 713) the board, faced with the facts of the case, took the view that a confidentiality agreement had - at least implicitly - been reached. This was perfectly sufficient. Furthermore, in line with general experience, it had to be assumed that such an agreement would be observed at least as long as there was a common concern for secrecy. Such concern would last at least for the period required to safeguard the interests of the business partners.
In T 799/91 the opponents asserted that the subject-matter claimed had been in prior public use in that its manufacture had been "sub-contracted out" to a third company. According to the board the third company was not simply any third party because the opponents' decision to place an order was based on a relationship of trust. The board therefore saw no indication of there having been prior public use, nor could the claim have been substantiated by the testimony of any witness.
In T 2/09 the board took the view that, where a party’s own interest in secrecy could be established, then the situation would be analogous to that of a non-disclosure agreement between the parties involved.
In T 274/12 the board concluded that there had been no implicit obligation to maintain secrecy. As evidence of public prior use, the appellants had cited documents they regarded as proof that a company had had talks with potential suppliers about developing a new product. The board shared the view taken by the German Federal Court of Justice (Bundesgerichtshof) in its decision X ZR 6/13 that an offer addressed not to the public but to a (potential) contractual partner could, in itself, be regarded as relevant prior art only if experience showed that the knowledge divulged in it to the recipient was likely to have been disseminated indiscriminately to third parties. According to the German Court of Justice, that could not readily be presumed where the offer related to the production of something yet to be developed, because both the party selected or wishing to develop it and the contractual partner wishing to benefit in some way from its development might have an interest in keeping the development project secret until the product went to market. An experience-based conclusion could be drawn only if at least one act of communicating knowledge as part of, for instance, an offer or delivery, was established which could then be assessed in the light of experience.