Constraint in Supplementary International Search

Constraint in Supplementary International Search

By Joseph Yang (Ella Cheong LLC)

As an applicant of PCT international patent application in Singapore, you may have been told that there is a process known as supplementary international search (SIS) which can provide you with greater visibility of the prior arts that may be used by an examiner to object to your patent application. In this short article, we would like to tell you a little more about SIS and particularly about some constraint currently existing in SIS. It is hoped that with better understanding, you can make better decision regarding your international patent application.

What is SIS?
Every PCT international patent application will go through a search of prior arts by an international searching authority (ISA). Prior arts are anything related to the patent application which have been made known to the public before the patent application is filed. The ISA is a patent office chosen by the applicant at the point of filing the international patent applicant for performing the search of prior arts. This is sometimes called the “main search”. After the main search is completed, the applicant has another opportunity to request for a “second search” of prior arts. This second search is the supplementary international search (SIS). While the main search is an essential part of the international patent application, the SIS is an optional process. The authority or patent office performing the SIS is known as Supplementary International Search Authority (SISA). It is required that the SISA be a different patent office from the ISA. By making it mandatory to use a different patent office as SISA, more comprehensive coverage of prior arts can be expected due to the complementary strengths of the two patent offices. The difference in strength or search capability is often in the area of linguistic searching capability. This special linguistic searching capability usually comes from the fact that a patent office in a country whose national language is not English often has in its collection patent documents in the national language of the country. When the patent office becomes a SISA, it often offers, as part of its SIS, the search of these documents held in its collection in addition to PCT minimum documentation.

Constraint in SIS
Being located in Asia, a Singapore patent applicant often files patent application in major Asian countries such as China, Japan and Korea, besides USA and Europe. If a Singapore patent applicant is interested in using SIS to uncover prior arts particularly in Chinese, Japanese and Korean languages, the applicant needs to know that, currently, only IPOS as an SISA includes in its search the Chinese documents held in its collection in addition to PCT minimum documentation. No SISA at the moment includes Japanese and Korean documents held in its collection in its search in addition to PCT minimum documentation. This is not surprising as patent offices of China (SIPO), Japan (JPO) and Korea (KIPO) are not part of the SISA. In fact, majority of the SISA are patent offices located outside of Asia. The applicant will have more options when SIPO, JPO and KIPO become SISAs and include in their search the documents in the respective national languages held in their collection. Having more patent offices in Asia joining as SISA will provide more options to the applicant and probably make the SIS more useful.

Even though JPO and KIPO are not available for use as SISA, they are among the ISA available for a Singapore applicant to choose from, besides IPOS, European Patent Office, Australian Patent Office and Austrian Patent Office. Therefore, given the current constraint, if a Singapore applicant is particularly concerned about prior arts in Japanese and Korean languages, the applicant can consider using JPO or KIPO as ISA to perform the main search.

We hope the information presented above will help you as a patent applicant to plan your international patent application better. For further advice on how to strategize your international patent application, please contact us.

If you have any questions on the above, please contact our Mr. Joseph Yang () or your usual contact. For similar updates, please visit