If the person who was able to gain knowledge of the invention was under an obligation to maintain secrecy, the invention cannot be said to have been made available to the public, provided the person did not breach that obligation. If the obligation to maintain secrecy stems from an express agreement that has been observed, the information has not been made available to the public. Less clear cut are cases of tacit secrecy agreements. Whether a tacit secrecy agreement between parties exists, depends on the peculiar circumstances of the specific case (T 1081/01, T 972/02, T 1511/06), e.g. the commercial inter‑relationship between and the commercial interests of the companies involved (T 913/01; see also T 830/90, OJ 1994, 713, T 782/92, T 37/98).

In T 1081/01 the board held that information provided subject to a confidentiality agreement did not become available to the public merely by reason of the expiry of the obligation to keep it confidential. Some separate act of making it available to the public would be needed. This conclusion was in agreement with the conclusion reached in T 842/91, where permission to publish a text was considered merely as permission to make the text available to the public, and not as actually making the text available to the public. In T 833/99 the board observed that there was no law to the effect that the confidentiality governing tender procedures ends when they do.

It is settled case law that – in the absence of any special circumstances – the sale of a device suffices to make it publicly available. What is often at issue here is whether there was any obligation to keep the device in prior use secret.