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Patents: Patent classification

An introduction to Patents and Patent databases

About patent classification

A patent classification system is an arrangement of hierarchical categories used to organize patents by their characteristics and relationships.

Until 2013 the USPTO used its own classification (USPC) to describe the categories.

The CPC (Cooperative Patent Classification) was co-developed with the EPO European Patent Office and is replacing the USPC by 2015.

Classification indexes

US Patent Classification

CPC (Cooperative Patent Classification)

Subject Guide