In T 472/92 (OJ 1998, 161) the board ruled that the existence of a joint venture agreement implied an obligation to maintain secrecy. It was found that an existing joint venture agreement would normally include an explicit or implicit confidentiality obligation between the common daughter and its parents.

In T 633/97 the opponent had to prove that an alleged prior use had in fact been made public, i.e. there was no obligation to maintain secrecy between the respective contractors. The board stated that, depending on the nature of the business relations and the status of the companies involved, the existence of such an obligation might be assumed on a prima facie basis without the necessity of a written agreement. In the case at issue, LLNL was acting in the national interest of the United States of America in fields which had to be considered classified. The very nature of this project, i.e. uranium enrichment technology, led to the conclusion that all persons involved had to be bound to secrecy.

Similarly, in decision T 1076/93, the board considered a weapons manufacturer normally not to form part of the public but to be implicitly supposed by its contractors to behave as if an agreement of secrecy had been specified (see also T 1619/06).

In T 163/03 the appellant (opponent) contended that the technical details of the apparatus as shown in the drawing D2 became state of the art when this drawing was given, without any confidentiality restriction, to BMW in May 1990, i.e. before the priority date of the patent in suit. The board held that where, as there, the terms and conditions of a technical cooperation, including related obligations of secrecy, had been explicitly specified and agreed upon by the partners of the cooperation by way of a written contract, the contractual provisions prevailed and left no room for construing implicit obligations of the parties which differed from or were incompatible with anything which the partners, on proper interpretation of the contract, had fixed therein. The board found that there was no reason whatsoever to assume, in the absence of any explicit secrecy obligation, that BMW could nevertheless have been under an implicit obligation to keep secret the manufacturing technology disclosed to it by the opponent within the framework of the SE project.