Patent classification

Patent databases contain a wealth of information about technology, and with 90 million patent documents the EPO's Espacenet worldwide database is one of the largest collections of technical information in the world. To make searching easier, patent applications are classified by technical area.

Here we look at current issues in patent classification, including the tagging schemes developed by the EPO to identify technologies that span multiple technical fields.


Its interdisciplinary nature means that the literature – especially patent documents – is difficult for searchers to retrieve. The EPO has therefore introduced "Y01N" tags to label nanotechnology in EPO databases. Recently Y01N became B82Y.

Climate change mitigation technologies

The EPO has also introduced a dedicated classification scheme ("Y02") to cover climate-change mitigation and smart grid technologies.

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