The Cooperative Patent Classification (CPC) is a harmonization of the U.S. and European existing patent classification systems, the European Classification System (ECLA) and the U.S. Patent Classification (USPC). The change to the CPC was initiated through a joint partnership between the United States Patent and Trademark Office (USPTO) and the European Patent Office (EPO). The CPC is the result of the USPTO’s effort to provide a modern classification system that is internationally compatible; and a result of the EPO’s effort to eliminate the reclassification of U.S. patent documents and ensure compliance with International Patent Classification (IPC), administered by the World Intellectual Property Organization (WIPO). The CPC is designed to have both US and European patent documents under a single classification scheme with a similar structure to that of the IPC. The joint classification system allows the USPTO and the EPO to efficiently share resources for classifying documents, revise the classification scheme where necessary, and to reclassify documents in an evolving world of technology.
In October 2010, the USPTO and EPO began working together to develop the CPC by incorporating the best practices of both the ECLA and USPC. The CPC was formally launched in January 2013, replacing the ECLA system at the EPO and initiating a two-year transition period at the USPTO for reclassification in an effort to begin phasing out the USPC in 2015. During this transition period the USPTO classified applications both in the CPC and the USPC systems while examiners received training on how to search in the CPC system and place CPC symbols on both granted patents and published patent applications. Going forward, both the EPO and USPTO will share maintenance of the CPC through a multi-year planning system for identifying areas requiring reclassification and a revised classification scheme. ECLA and USPTO symbols will not be removed from patent documents published prior to January 2013 and January 2015, respectively, for historical searching.
Two main objectives were theorized for the transition to the CPC. First, to improve patent searching by creating a more developed classification that the already existent IPC. Second, to efficiently share resources between the USPTO and EPO. Objectives, Cooperative Patent Classification. With these objectives in mind, the expected benefits of the CPC were enhanced examination efficiency, improved access to documents from patent offices around the world, improved navigation and understanding of a single classification system, improved consistency of search results across offices, facilitated work-sharing on applications filed across offices, and more adaptive and actively maintained classification schemes.
The transition to the CPC from the USPTO and ECLA has created a number of new obstacles for searchers and attorneys in the patent searching world. The CPC is divided into nine sections which are then subsequently divided into classes, sub-classes, groups, and sub-groups. In total, the CPC contains approximately 260,000 classification entries. The greater number of classification entries than previously used provides a more detailed scheme breakdown and more descriptive classification titles. See Cooperative Patent Classification(CPC): General Introduction into CPC, United States Patent and Trademark Office (July 10, 2012). As a result, a best practice for searchers and attorneys using the CPC is to understand the more detailed breakdown and recognize that a particular feature may be covered by multiple classes.
The CPC is one scheme that includes an indexing system, which resembles the current IPC indexing system. In the CPC, all symbols belong to a single scheme but differentiate by use and scope, rather than the use of different symbols for each ECLA and USPC scheme. Available tools for searching in the CPC system include the CPC concordances with the ECLA and IPC, and statistical mapping tools from USPC to CPC. The CPC website provides CPC concordances tables for ECLA to CPC and CPC to IPC for reference. Each table provides a conversion of ECLA classifications to CPC classifications or CPC classifications to IPC classifications. For example, a patent classified under a particular ECLA classification is aligned with the respective CPC classification for that patent.
Furthermore, the USPTO provides a statistical mapping tool for mapping from USPC to CPC. The statistical mapping is produced by a statistical analysis of symbols allocated to families of documents classified simultaneously in the CPC and USPC schemes. Each USPC symbol is mapped to a CPC symbol and possibly additional CPC symbols depending on relevance and contribution. Confidence in statistical mapping is low when the statistical results of mapping of one USPC symbol to many CPC symbols is large or the number of families having the corresponding CPC symbol statistically analyzed is small. See Statistical Mapping: FI to CPC, European Patent Office (July 20, 2016). For example, a USPC symbol allocated to a certain family of documents can be mapped to at least one CPC symbol when the statistical mapping returns (in between brackets), first, the number of families bearing the corresponding CPC symbol, and second, the percentage that these corresponding families represent over the total number of families classified under that CPC classification. If the number of families found bearing the corresponding CPC symbol is less than 3, the mapping will return “NOMAP”, meaning that no mapping is possible. Moreover, searchers and attorneys should note that mapping from USPC to CPC may not be reliably precise because mapping is based on statistical analysis due to the fact that the USPC is not based on IPC/ECLA systems.
Searchers and attorneys should also note that any saved alerts or saved search queries based on USPC will no longer return results (after 2015), and may need to be updated. Likewise, any historical search queries based on USPC will not return results (after 2015) if conducted today.