Subject-matter described in a document can only be regarded as having been made available to the public, and therefore as comprised in the prior art pursuant to Rules 33 and 64, if the information given therein to the skilled person is sufficient to enable them, 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 them.[Rule 33; Rule 64; GL/ISPE 12.02; ]

Similarly, it should be noted that a chemical compound, the name or formula of which is mentioned in a prior-art document, is not thereby considered as known, unless the information in the document, together, where appropriate, with knowledge generally available on the relevant date of the document, enables it to be prepared and separated or, for instance in the case of a product of nature, only to be separated.

The EPO applies option GL/ISPE A12.02[1] of the Appendix to Chapter 12 of the ISPE Guidelines.