According to the established case law a disclosure destroys novelty only if the teaching it contains is reproducible, i.e. can be carried out by the skilled person (T 1437/07, T 1457/09). Subject-matter described in a document can only be regarded as having been made available to the public, and therefore as comprised in the state of the art pursuant to Art. 54(1) EPC, if the information given therein to the skilled person is sufficient to enable him, at the relevant date of the document, to practise the technical teaching which is the subject of the document, taking into account also the general knowledge at that time in the field to be expected of him (see T 26/85, T 206/83, T 491/99, T 719/12 and Guidelines G‑VI, 4 – November 2018 version).

In T 206/83 (OJ 1987, 5), in particular, it was found that a document did not effectively disclose a chemical compound, even though it stated the structure and the steps by which it was produced, if the skilled person was unable to find out from the document or on the basis of his common general knowledge how to obtain the required starting materials or intermediates. Information which could only be obtained after a comprehensive search was not to be regarded as part of the common general knowledge. This need for an enabling disclosure was also in conformity with the principle expressed in Art. 83 EPC 1973 for patent applications which had, accordingly, to "disclose the invention in a manner sufficiently clear and complete for it to be carried out by a person skilled in the art". The requirements as to the sufficiency of the disclosure were, therefore, identical in all these instances.

In T 719/12 neither party contested that document (1) disclosed the compound methyl-2-(α-thenoyl)-ethylamine by name. The board held that document (1) alone did not make the compound available to the public, since the specific attempts to prepare it which were described in that document had failed. Therefore, the board concluded that it had not been made available to the public, as no method for its preparation had been available at the publication date of the prior art.

For selection inventions the requirement of a reproducible disclosure also plays a significant role. In T 26/85 (OJ 1990, 22) the ranges of a certain parameter as defined in the claim fell within the broader ranges stated for the same parameter in a prior art document. The board considered that a realistic approach, when assessing the novelty of the invention under examination over the prior art in a case where overlapping ranges of a certain parameter existed, would be to consider whether the person skilled in the art would, in the light of the technical facts, seriously contemplate applying the technical teachings of the prior art document in the range of overlap; if it could be fairly assumed that this would be the case, it had to be concluded that no novelty existed. Such was not the case in the matter under consideration, since there existed in the prior art a reasoned statement clearly dissuading the person skilled in the art from using the range under a certain value, and the range of overlaps was under this value; the claimed range was therefore considered novel (see also T 255/91).

In T 447/92 the board held that the cited document did not disclose when or how far a movable piece in the claimed invention (an air circuit breaker) moved, or the way in which it worked to prevent the spring-back of a lever. No relative movement was described or shown in the drawings and it was a matter of conjecture as to the manner in which the relevant parts co-operated. The board found that it might have been obvious to a skilled person that the notch could co-operate with the shaft in the manner defined in the claims of the patent in suit, but that this only meant that the disclosure took him close enough to do the rest himself. It did not mean that the document took the skilled person all the way to the present invention. Thus, the features of the air circuit breaker according to claim 1 of the application were not unambiguously derivable from the drawings of an earlier European patent application.

In T 310/88 the board of appeal had to consider a discrepancy between what actually happened in practice when carrying out a technical teaching in a prior document according to the letter of its description, and what this prior document said would happen. The board held that the invention was novel over the prior document because the latter did not contain a sufficiently clear teaching for that conclusion not to be reached (see T 23/90).

In T 491/99 the board held that an earlier patent, which used terminology which at first sight was suggestive of the product invention claimed, was not in fact a prejudicial disclosure if a skilled person could actually only make the product in question later, from the process and machine described for the first time in the European patent in suit.

In T 1437/07 the board pointed out that a disclosure in a prior art document is novelty-destroying only if the teaching it contains is reproducible. This need for an enabling disclosure is in conformity with the principle expressed in Art. 83 EPC. Thus, the requirements of sufficiency of disclosure are identical for a prior art document and a patent. The board followed the principles developed by the case law in the framework of the evaluation of the requirements of Art. 83 EPC in the case of a medical use, i.e. that the skilled person should not only be able to carry out the teaching of the prior art document, but it should also be credible that the effect at issue – here, relief of pain – has been achieved (see also T 491/08).

In T 578/12 the appellant contested that claim 1 of the main request was not new in view of prior art document D1, an Australian patent application; its main argument was that D1 had no drawings or any description of a detailed embodiment of any dispensing machine and could not be regarded as an enabling disclosure. The board noted inter alia that the fact that D1 did not contain any figures did not hinder the skilled person from understanding the described method or from carrying it out. The decision in this case gives an example of a detailed set of reasons for the outcome of examining features disclosed by a prior-art document.

In T 1457/09 claim 4 was drafted as a second medical use claim. In the decision under appeal the opposition division held that the subject-matter of the corresponding claim was anticipated by the intermediate document (D1). The opposition division considered that both documents (D1) and (D1a, the priority document of D1) disclosed pharmaceutical compositions comprising the peptide RMFPNAPYL and their use as a cancer vaccine. The board found that for the requirement of reproducibility to be considered as fulfilled in relation to a medical use it is necessary that the disclosure in the prior-art document is such as to make it credible that the therapeutic effect on which the disclosed treatment relies can be achieved (T 609/02). The board held that in the case at issue a prior art document was novelty-destroying only if it disclosed not only the product referred to in the claim – here RMFPNAPYL – for the claimed therapeutic application – here treatment of cancer – but also that the claimed product was indeed suitable for the claimed therapeutic application. The board concluded that the experimental results disclosed in document (D1a) were not sufficient to make it credible that the RMFPNAPYL peptide was suitable for the treatment of cancer. Therefore document (D1) did not destroy the novelty of the subject-matter of claim 4.