The CPC codes have been developed jointly by the European Patent Office (EPO) and the US Patent Office (USPTO). WIPO, China and Korean offices use this classification from 2016 on each new publication.
From January 1, 2013, the EPO examiners attribute CPC classification codes to new patents. Patent classified with ECLA/ICO codes have been reclassified with the CPC codes based on a conversion table established by the EPO.
Until the December 31, 2014, the USPTO can classify applications with CPC and PCL codes, while issued patents are classified with either CPC and PCL codes or just PCL codes.
There are about 280,000 CPC codes.
Conversion rules:
Their format is based
on the IPC codes
The letters of the subdivisions of the ECLA codes are
replaced by numbers. There may be up to 6 digits after the / separator
The
ICO mirrors are incorporated into the CPC codes
The Y section of the ICO
codes is fully established.
For ICO orthogonal codes, a 2 is added after the
subclass to create a CPC 2000 series
Example: A61H-2230/04
Schematic of a CPC
code:
Position 1: section (A to H and Y)
=>H
Positions
2 and 3: class
=>H01
Position 4: subclass
=> H01L
Positions 5 to 8: main group
=>H01L-021
Position 9: separator
=>H01L-021.
Positions 10 to 15: subgroup
=>H01L-021/28264
These codes can be searched at the section, class etc. levels.
The notes in brackets are the ECLA classifications that have been preserved in the CPC classification.