Patent Knowledge Center 1 Basic Concepts 1.2 Classification Systems

1.2 Classification Systems

In all jurisdictions, all patent documents are classified into different codes representing different fields of inventions. There are many classification systems in the world. Among them, the most populat ones are the International Patent Classification (IPC), the  Cooperative Patent Classification (CPC), and the legacy European CLAssification (ECLA) and the United States Patent Classification (USPC).


1.1.1         IPC

IPC is provided by the World Intellectual Property Organization (WIPO). It is a system based on hierarchical structures of symbols.  The layers of IPC symbols are: section (subsection); class; subclass; group (main group, subgroup); complete symbol.

Example: H04W 08/10

Section: H->Electricity

Class: H04->Electric Communication Technique

Subclass: H04W->Wireless Communication

Main group: H04W 08/00->Network data management

Subgroup: H04W 08/08->..Mobility data transfer

Complete Symbol: H04W08/10->…between location register and external networks


1.1.2         CPC

CPC is a product of joint efforts from EPO and USPTO to harmonize ECLA and USPC so that EPO and USPTO would share the same classification system. CPC is based on ECLA and backward compatible with IPC.  CPC has a similar structure to IPC but have more symbols.


SIPO also migrated to CPC and all new Chinese patent documents are classified with CPC.


1.1.3         EPLA and USPC

ECLA is the legacy classification system used in EPO. ECLA is no longer in use for new patent documents after January 2013.


USPC is no long in use for new patent documents after January 2015 after USPTO migrated to CPC.

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