Re-Classifying Patent Search- Cooperative Patent Classification (CPC)

This post was first published on 4th November, 2011.

One of the strategies adopted by the examiner/searcher while performing a prior art search is to identify the classification of the invention’s subject matter. Patent classification is a way by which a patent office arranges identical or similar patent documents. A patent document can be classified in several classes.

There are numerous patent classification systems available across the world such as International Patent Classification (IPC), United States Patent Classification (USPC), European Classification (ECLA), F-term and Derwent classification system. Most of the countries incorporate IPC on their patent documents. The IPC is generated by using a computer concordance and hence, many people believe that the IPC on a patent document is often quite broad and more general.

Generally, there is often no exact relationship between different classification systems. For example, US classification introduced in 1836 does not have any exact relationship with International Patent Classification (IPC) introduced in 1968. In order to overcome aforementioned problem between different classification systems, European Patent Office (EPO) and US Patent and Trademark Office (USPTO) launched a joint project in Oct 2010 to create the Cooperation Patent Classification (CPC) in order to harmonize their patent classifications systems (ECLA and USPC respectively) into a single system having a similar structure to the International Patent Classification (IPC) administered by the World Intellectual Property Organization (WIPO), the only patent classification system used by all patent offices. Further, the CPC system will be more detailed than the IPC to improve patent searching and examination. It is believed that the new CPC will use the European Classification system (ECLA) as a basis and incorporate the best classification practices of the USPTO.

Further, the EPO and the USPTO will share their resources in order to classify documents, to revise the scheme whenever necessary and to subsequently reclassify documents in order to reduce unnecessary duplication of work and enhance efficiency.

References: Intellogist and britishlibrary

Image by Kevin Spear

Author: Sanjiv Saran


  • November 4, 2011 Posted
    Ritesh Jain

    Following are my cencerns:

    If CPC were different from the IPC/ELCA, How would it help the examiners in conducting an exhaustive search for the references which got published before CPC came in to existance? …


    Form the website, it seems that CPC would be more or less similar to the present IPC/ELCA except for the characters on the extereme right of the classification…again as a searcher I am keen to learn about it absolute benefits for an exhaustive search

    I look forward for counterviews. ..Thnx

  • November 8, 2011 Posted
    Sanjiv Saran

    EPO and USPTO will maintain a collaborative scheme by sharing the resources for joint classification. The searcher/examiners can perform a search and retrieve relevant patent documents which are classified under same class across different patent offices. This will surely increase the efficiency.

    Nothing has been disclosed by CPC group about reclassifying the existed patent documents. However, it appears that USPTO and/or EPO may take initiative to come up with some idea to classify patent documents already published.

    In my opinion CPC will take the structure of IPC and classification category of ECLA and USPC

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