With regard to the public availability of commercial brochures, some boards adopt the less strict standard of the "balance of probabilities" (see e.g. T 743/89 and T 804/05). Following that case law, the board in T 1140/09 considered the "balance of probabilities" to be the proper standard of proof to be applied for the question of the public availability of document E3, a brochure that had been distributed by the appellant to visitors at CeBIT and had therefore been made available to the public before the priority date. In the particular case, however, the evidence presented by the appellant was such that it also met the stricter standard of proof as proposed by the respondent. Given the importance of large industrial fairs such as CeBIT for doing business and the strong interest of the appellant in making its brochure as widely available as possible, the board found that the public availability of document E3 was proven beyond reasonable doubt.
In T 151/99 the board regarded it as highly plausible in the light of the available evidence that a master's thesis had become available to at least one member of the public. If the reference was in a document published before the priority date of the patent in suit then it could be assumed that the thesis had also been made available to the public before the said date.
In T 1134/06 the board pointed out that, as a first step in evaluating evidence, the reliability of the source had to be ascertained. Where, for the purposes of assessing novelty and inventive step, the state of the art under Art. 54(2) EPC is established on the basis of traditional publications such as published patent applications or specifications, the majority of these publications emanate from sources which are considered as reliable. The evidentiary weight of such sources normally resides in the large number of physical, existing copies of the publication, or because the source itself has the character of public authority, such as a patent office. Therefore, publication date and content are assumed to be truthful with a high level of confidence. In the case at issue, however, the disclosure had been made available to the public on the Internet. In order to establish that an internet disclosure formed part of the state of the art, the board held that the same strict standard of proof as for prior use or prior oral disclosure had to be applied – the same questions "when", "what" and "under which circumstances" had to be answered (endorsed by T 1875/06). Furthermore, the board took the view that the circumstances which allowed the determination of whether a disclosure on the Internet had been made available to the public might, where appropriate, also include factors that had a bearing on the reliability of the information, for example, the manner in which information had been procured and date stamped, how it had been preserved by the source, and whether it had remained unaltered since deposit.