Are you getting more questions about the Cooperative Patent Classification (CPC) system now that U.S. patent documents are finally beginning to appear without the once familiar U.S. Patent Classification (USPC) codes?

Do you want to be a benevolent resource for those colleagues who had been blissfully ignoring the CPC until now?

Or do you just want some resources to recommend to colleagues, clients or students, so that you can get back to doing your real job?

The Transition to CPC is Over

Now that it is well into 2015, you may be getting more questions from users wondering where the USPC codes have gone, and you may also be getting questions about the structure and usage of CPC itself, especially from users who have relied primarily upon USPC for searching or analysis.

Helpful Resources at the EPO

As much as the USPTO is (and continues to be) a full partner in the development of the CPC scheme, I would recommend the EPO’s site for documentation and training on CPC.

The EPO retired their old system, ECLA, as of January 1, 2013, and thus completed their transition to CPC a full two years ahead of the USPTO. The CPC system also has its roots in ECLA, an IPC-based system just like CPC. The EPO has had a long time to figure out how to teach others about IPC-compliant classification systems such as CPC.

Here are my two favorite places to go for CPC information at the EPO:

1. The EPO’s CPC Search Tool

The EPO has a great online tool for browsing the CPC scheme. In addition to being a great tool for finding appropriate CPC codes, the browser also functions as an excellent learning resource.

The CPC classification browser allows users to search the CPC via keywords or classification codes, and provides user documentation via a tidy, user-friendly interface. The tool provides a hierarchical view of the classification scheme that can be visually expanded and contracted to show varying degrees of detail, including definitions, usage notes, warnings, and information about current developments, such as re-classification efforts.

The compact visual layout of the tool, coupled with the ability to show and hide detail as needed, helps users explore extensive CPC documentation while still keeping users aware of the conceptual hierarchy underlying the classification scheme.

2. The EPO’s E-Learning Centre

The EPO maintains an E-learning Centre with self-directed study modules and regular live webinars. The EPO has more recently added more live webinars at times suitable for audiences in the Americas.

I have found the EPO study modules to be easy to access, straightforward, and clear. You can find existing CPC-specific modules by looking for the EPO’s e-learning courses. As of Spring 2015, CPC courses can be found along this path: Modules on Selected Topics> Searching for Patents > Classification.

Watch this Space at the USPTO

The USPTO also maintains CPC-related links on its Classification Standards and Development page.

At present, I find the USPTO’s resources less helpful than those provided by the EPO, but this should change as the USPTO settles in with CPC. Right now, one can look up CPC codes in the USPTO CPC schedule, and use the USPTO’s statistical mapping tool to match CPC codes to given USPC codes. Having explored both sites, I prefer the EPO implementation for now.

I am hoping that the USPTO will devote some special attention to helping devoted USPC users develop a good understanding of the conceptual structure of CPC. Concordances can be useful, but they are no substitute for a good understanding for the classification system in use. Some current examples of USPTO-developed training materials can currently be found at

Mastery Is A Journey: Stay Current With

The CPC is, and will continue to be, a moving target. Just as the technologies the scheme is designed to describe will change, so will the scheme itself.

Going forward, best place to keep up with changes to the CPC classification will be the USPTO and EPO’s joint website for CPC-related events and information,

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