In T 541/92 a sub-contractor had given sketches of a device to its client. In the board's view this constituted an obligation to maintain secrecy. It was standard practice for clients and their subcontractors to keep their projects secret, and allegations to the contrary required convincing proof. Likewise in T 887/90 the obligation to maintain secrecy was derived from the circumstances.
In T 1076/93 the opponents had, without there having been an explicit agreement to maintain secrecy, had offered an apparatus which caused the subject-matter of the invention to lack novelty and had provided drawings to a weapons manufacturer. The board held that the prior use did not cause lack of novelty, because a variety of circumstances pointed to there having been an obligation to maintain secrecy. According to the board, discretion was generally acknowledged to be the rule on the premises of such companies.
In T 818/93 several steps and approaches had been taken within the context of business relationships which were necessary to bring the project to a successful conclusion. The board held that such negotiations were confidential by nature, in view of the comparable interests of the parties involved, and implied a secrecy agreement.
In T 480/95 the document relied upon by the opposition division as a prepublication decisive for the evaluation of inventive step was a letter from the opponent to a customer written in connection with a contractual relationship between the two firms. The board considered this letter to be a typical example of correspondence between contracting firms, which was confidential by its very nature.