Patent Cooperation Treaty (PCT)
Article 15
The International Search
(1) Each international application shall be the subject of international search.
(2) The objective of the international search is to discover relevant prior art.
(3) International search shall be made on the basis of the claims, with due regard to the description and the drawings (if any).
(4) The International Searching Authority referred to in Article 16 shall endeavor to discover as much of the relevant prior art as its facilities permit, and shall, in any case, consult the documentation specified in the Regulations.
(5)(a) If the national law of the Contracting State so permits, the applicant who files a national application with the national Office of or acting for such State may, subject to the conditions provided for in such law, request that a search similar to an international search ("international-type search") be carried out on such application.
(b) If the national law of the Contracting State so permits, the national Office of or acting for such State may subject any national application filed with it to an international-type search.
(c) The international-type search shall be carried out by the International Searching Authority referred to in Article 16 which would be competent for an international search if the national application were an international application and were filed with the Office referred to in subparagraphs (a) and (b). If the national application is in a language which the International Searching Authority considers it is not equipped to handle, the international-type search shall be carried out on a translation prepared by the applicant in a language prescribed for international applications and which the International Searching Authority has undertaken to accept for international applications. The national application and the translation, when required, shall be presented in the form prescribed for international applications.