Another argument sometimes used is that information was given only to a limited circle of people and was therefore not publicly available.
The boards have held repeatedly that the information is publicly available where it was made available to a limited circle of people (T 877/90 - congress; T 228/91 - course; T 292/93 - demonstration for potential customers conducted on the premises of a company with close links to the opponent).
In T 877/90 an oral disclosure was regarded as made available to the public if, at the relevant date, it was possible for members of the public to gain knowledge of the content of the disclosure and there was no bar of confidentiality restricting the use or dissemination of such knowledge. It was plausible that the meetings in question were not open to everybody, because only certain persons were invited to participate. Those, however, were not subject to a secrecy agreement. So the oral disclosure of the meetings was freely available to the public. Everything that was said at the meetings was therefore made available to the public.
In T 300/86, in the opinion of the board, a written description was to be regarded as made available to the public if, at the relevant date, it was possible for members of the public to gain knowledge of the content of the document and there was no bar of confidentiality restricting the use or dissemination of such knowledge. This was in agreement with the Guidelines. The group of persons to be taken into account as the public within the meaning of Art. 54(2) EPC 1973 was naturally defined by the circle of persons to whom the content of the document might be of interest. All the interested parties had to have the opportunity of gaining knowledge of the content of the document, however unrestricted by contractual or other legal restrictions on use or dissemination of the information therein. Otherwise the document had not been made available to the public.
In T 1081/01 the board observed that if, at the time of receipt of the information, the recipient was in some special relationship to the donor of the information, he could not be treated as a member of the public, and the information could not be regarded as published for the purpose of Art. 54 EPC 1973. Even if this special relationship were later to cease, so that the recipient was now free to pass on the information, the mere cessation of the special relationship did not make the information available to anyone else (see also T 1057/09).
In T 398/90 a marine engine installed in a ship was held to have been known to the engine room crew and hence to have been made available to the public.
In T 165/96 the board held that "the public" within the meaning of Art. 54(2) EPC 1973 did not presuppose a minimum number of people or specific educational qualifications; the residents of a Copenhagen suburb sufficed.