4.2.2.6 Classification using C-sets

Also in this Chapter:

• 4.2.2.1 Invention Information and Additional Information
• 4.2.2.2 Classification Priority Rules
• 4.2.2.3 Classifying in Function-Oriented and Application-Oriented Places
• 4.2.2.4 Classifying Chemical Compounds
• 4.2.2.5 CPC Classification Rules​​​​​​​

Sub-chapters

• 4.2.2.6.1 Information Value of the Allocation
• 4.2.2.6.2 Allocation of C-Sets to a Document
• 4.2.2.6.3 C-Sets Syntax Rules
• 4.2.2.6.4 Guidance about C-Sets Information in Scheme and Definitions

The rules of C-Sets are specific for each technical field. C-Sets may also be referred to as ‘combination sets’ or ‘combination classes’ or the explanation may just mention that the classification is to be done as a combination of symbols.

The definition statement for a subclass may indicate areas in the subset in which C-Sets can or must be used, but specific information about how to create a C-Set in a particular technical area can usually be found in the definition or notes for the relevant sub-group or group (e.g. C12N 15/10).

To ensure classification accuracy and consistency, C-Sets classification is authorised only in a limited number of CPC subclasses. The Table in Annex III of the CPC Guide lists those subclasses authorised for C-Sets allocation. As shown in the Table, not all groups within the authorized subclasses are allowed for C-Sets allocation.

Example: In subclass C07C it is not allowed to allocate a C-Set with a base symbol in group C07C9/00. It is also not allowed to allocate a C-Set with a subsequent symbol in group C07C1/00.