PCT International Search and Preliminary Examination Guidelines
15.08 The international search is carried out and the international search report prepared by an International Searching Authority. The international search itself is normally performed by one examiner but is not limited to one. In appropriate cases, where the invention is of a nature requiring searching in widely dispersed specialized fields, an international search report containing the work of two or more examiners may be necessary.
15.09 The examiner is also required to provide a written opinion on novelty, inventive step and industrial applicability of the claimed invention at the same time as he establishes the international search report. The international search report and written opinion together serve to inform the International Preliminary Examining Authorities of the documents and arguments necessary to complete the relevant assessments themselves if a demand for international preliminary examination is made, as well as to inform the designated Offices for the purposes of their consideration of the application in the national phase (the written opinion being transmitted to them in the form of an international preliminary report on patentability (Chapter I of the Patent Cooperation Treaty) if no international preliminary examination report is established under Chapter II of the Treaty). Consequently it is essential that the examiner is familiar with the requirements of examination. In order to provide applicants and third parties with high levels of predictability for the potential outcomes of future national or regional prosecution, examiners should endeavor to prepare high quality international search reports and written opinions as foreseen under Chapters 2, 9 and 15 so that they can confidently be used by designated and elected Offices.