Under the PCT, an invention is considered to be novel if it is not anticipated by the prior art. Everything which is made available to the public anywhere in the world by means of a written disclosure is considered prior art provided that such making available occurred prior to the relevant date. In cases where the making available to the public occurred by non-written means, it constitutes prior art only if a written disclosure that occurred before the relevant date confirms the non-written disclosure. The relevant date is the international filing date or, where at least one priority has been validly claimed, the date of the earliest priority. It should be noted that in considering novelty (as distinct from inventive step), it is not permissible to combine separate items of prior art together. It is also not permissible to combine separate items belonging to different embodiments described in one and the same document, unless such combination has specifically been suggested, see also ISPE Guidelines 12.06.[Art. 33(2); Rule 43bis.1(a)(i); Rule 64.1; Rule 64.2; GL/ISPE 12.01; 12.02; ]

For the specific case of selection inventions see ISPE Guidelines 12.10.

Furthermore, any matter explicitly disclaimed (with the exception of disclaimers which exclude unworkable embodiments) and prior art acknowledged in a document, insofar as explicitly described therein, are to be regarded as incorporated in the document.

It is further permissible to use a dictionary or similar document of reference in order to interpret a special term used in a document.[GL/ISPE 12.06; ]