4.2.2.5 CPC Classification Rules

Date Published

CPC classification rules are the same as IPC classification rules with a few additions. Guide to the CPC is a comprehensive guide to the classification rules of the CPC.

In the CPC, it remains the practice to assign the indexing codes of the 2000-series, i.e. (further) breakdown and/or orthogonal indexing codes and/or IPC indexing codes, to identify further elements of information about a technical subject of the invention already classified as such by appropriate main-trunk classification symbols. In particular, allocation of the indexing codes can cater for a more accurate classification than the main-trunk symbols or can reflect another aspect of the inventive subject matter.

Application of CPC indexing codes can be either desirable only or obligatory, and the specifications as to the intended usage of the indexing codes (namely desirable vs. obligatory) should be found in the Definitions.