To make searching easier, every patent is classified. A classification scheme is a system of codes that groups inventions according to technical area.
Patent offices worldwide use the International Patent Classification (IPC) . There are approximately 70 000 different IPC codes for different technical areas.
The Cooperative Patent Classification (CPC) is an extension of the IPC and is jointly managed by the EPO and the US Patent and Trademark Office.
CPC includes an additional section Y related to general tagging of new technological developments, which is also sub-divided into classes, sub-classes, groups and sub-groups.