Administrative Instructions under the Patent Cooperation Treaty

Section 504
Classification of the Subject Matter of the International Application

(a)  Where the subject matter of the international application is such that classification thereof requires more than one classification symbol according to the principles to be followed in the application of the International Patent Classification to any given patent document, the international search report shall indicate all such symbols.

(b)  Where any national classification system is used, the international search report may indicate all the applicable classification symbols also according to that system.

(c)  Where the subject matter of the international application is classified both according to the International Patent Classification and to any national classification system, the international search report shall, wherever possible, indicate the corresponding symbols of both classifications opposite each other.

(d)  The version of the International Patent Classification applicable at the time the international application is published under Article 21 shall be used whenever feasible.