When dealing with a new application case which is a PCT application entering the Chinese national phase, a patent agent usually encounters documents entitled Written Opinion of the International Searching Authority and International Preliminary Report on Patentability. When submitting a PCT-PPH request for an application based on a PCT international phase work result, it is required that the latest work result of PCT application international phase of the application should be Written Opinion of the International Searching Authority (WO/ISA), Written Opinion of the International Preliminary Examining Authority (WO/IPEA) or International Preliminary Examination Report (IPER). Then, what is the relationship between Written Opinion of the International Searching Authority, Written Opinion of the International Preliminary Examining Authority, International Preliminary Examination Report, and International Preliminary Report on Patentability?

Clarifying the relationship between the opinions or reports will greatly improve the quality of dealing with a new application case which is a PCT application entering the Chinese national phase, and the passing rate of a PCT-PPH request. Hereinafter, the writer will organize the relationships between the several opinions or reports as mentioned above.

I. International Search

The international search is a procedure necessarily performed on a PCT application according to Chapter I of the PCT; and except the cases for which a search is not required as provided in PCT Rule 39.1, a majority of PCT applications must be subjected to international search by the International Searching Authority (ISA). After the International Searching Authority searches a PCT application, a written opinion will be written while a search report is written, and in this opinion, with regard to the problem whether the invention concerned complies with the criteria for being granted a patent right, a preliminary and unconstrained opinion is provided. The written opinion written by the International Searching Authority after searching the PCT application is "Written Opinion of the International Searching Authority" (WO/ISA). This opinion is sent to the applicant and the International Bureau (IB) together with the International Search Report.

After the applicant receives the written opinion of the International Searching Authority, the applicant can propose his own opinion to the IB with regard to the written opinion or make modifications to the claims of the PCT application according to the provisions of PCT Article 19, but the International Searching Authority will not respond to the applicant's reply. The applicant may also not make any response to the Written Opinion of the International Searching Authority.

II. International Preliminary Examination

The international preliminary examination is an optional procedure carried out according to Chapter II of the PCT, in which the applicant submits an international preliminary examination request according to his/her own requirements, and then the PCT application is further examined by the International Preliminary Examining Authority (IPEA).

If the applicant does not request an international preliminary examination on the PCT application, then the "Written Opinion of the International Searching Authority" will constitute an "International Preliminary Report on Patentability", and the IB reports the "International Preliminary Report on Patentability" to a designated bureau of the PCT application together with the response from the applicant and discloses same to the public.

If the applicant requests an international preliminary examination on the PCT application, then the applicant may submit a detailed discussion on the patentability of the claims to the International Preliminary Examining Authority with regard to the Written Opinion of the International Searching Authority, or make modifications to the claims, the description, the accompanying drawings, etc. of the PCT application according to the provisions of PCT Article 34 while making a detailed discussion on the patentability of the claims.

After performing international preliminary examination on the PCT application, if the International Preliminary Examining Authority has an examination opinion consistent with the "Written Opinion of the International Searching Authority" provided by the International Searching Authority, then the International Preliminary Examining Authority will take the "Written Opinion of the International Searching Authority" as Written Opinion of the International Preliminary Examining Authority, and send same to the applicant and the IB. At this time, the "Written Opinion of the International Searching Authority" as the Written Opinion of the International Preliminary Examining Authority will constitute an "International Preliminary Report on Patentability", and the IB reports the "International Preliminary Report on Patentability" to a designated bureau of the PCT application together with the response from the applicant and discloses same to the public.

After performing international preliminary examination on the PCT application, if the International Preliminary Examining Authority has opinions different from those of the International Searching Authority, then the International Preliminary Examining Authority will issue a Written Opinion of the International Preliminary Examining Authority which is different from the Written Opinion of the International Searching Authority, i.e. an International Preliminary Examination Report, and will send the International Preliminary Examination Report to the applicant and the IB. At this time, the International Preliminary Examination Report will constitute an "International Preliminary Report on Patentability", and the IB reports the "International Preliminary Report on Patentability" to a designated bureau of the PCT application together with the response from the applicant and discloses same to the public.

III. Summary

It can be determined therefrom that the Written Opinion of the International Preliminary Examining Authority can be the Written Opinion of the International Searching Authority or the International Preliminary Examination Report, but the Written Opinion of the International Preliminary Examining Authority does not necessarily exist in the international phase of a PCT application. The International Preliminary Report on Patentability may include a Written Opinion of the International Searching Authority or an International Preliminary Examination Report. In the case where the applicant does not propose an international preliminary examination request on the PCT application, and the applicant proposes an international preliminary examination on the PCT application but the examination result of the International Preliminary Examining Authority is consistent with the examination result of the International Searching Authority, then the International Preliminary Report on Patentability is the Written Opinion of the International Searching Authority. In the case where the applicant proposes an international preliminary examination on the PCT application, but the examination result of the International Preliminary Examining Authority is inconsistent with the examination result of the International Searching Authority, then the International Preliminary Report on Patentability is the International Preliminary Examination Report. The International Preliminary Report on Patentability necessarily exists at the international phase of a PCT application. As for the relationship between Written Opinion of the International Searching Authority, Written Opinion of the International Preliminary Examining Authority, International Preliminary Examination Report, and International Preliminary Report on Patentability, please refer to the figure below.

The content above is summary and organization of the writer regarding the relationship between the opinions or reports, which is only used for your reference. If there are any inaccuracies, please do not hesitate to correct them.