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 (decision analysed more recently in T 538/09, which concerns a master's thesis of the first examiner as prior art; also citing T 1134/06 and T 750/94 in that an important criterion in evaluating evidence is the reliability of the source: fullfiled for University of Utah). The strict standard of proof (beyond reasonable doubt) laid down as the rule for internet publications in T 1134/06 no longer applies since T 286/10 and T 2227/11, both found the balance of probabilities to be the usually applicable standard.

In T 1469/10 the board held that the publication dates indicated on the documents published by the ETSI 3GPP organisation, which was regarded as a reputable standardisation body having clear and reliable rules for their publications, were of a high probative value and thus might serve as prima facie evidence that a document was published on the date indicated, and regarded the documents at issue thus as representing the state of the art under Art. 54(2) EPC.

As a matter of principle, if an adverse decision of an organ of the EPO is to rely on a certain fact that fact should be proven beyond any reasonable doubt. In T 826/03, the board applied this principle when attempting to establish the publication date of a Canadian patent application, and whether it was prior art. It found that in view of the contradictory evidence on file and in the absence of any further clarifying information from the Canadian Intellectual Property Office, it was virtually impossible for the board to establish with certainty that the public had access to the application according to document D3 before the priority date claimed by the application in suit. It therefore considered document D3 as not belonging to the prior art within the meaning of Art. 54(2) EPC.