What is a C-STAR (C*) in CPC classification?
A C-STAR (C*) is an important designation in the Cooperative Patent Classification (CPC) system. According to MPEP 905.03(a):
“A C-STAR (C*) is applied to an allocated symbol from the classification picture on an application when that symbol represents at least one concept that is claimed.”
Key points about C-STAR:
- It is mandatory to apply C* designations.
- C* applies to symbols representing claimed concepts, regardless of type or position.
- No new CPC symbols should be allocated solely for C* purposes.
- Narrow/specific CPC symbols falling within claimed subject matter should be designated as C*.
- At least one CPC symbol must be designated as a C*, but there’s no upper limit.
C-STAR helps identify which parts of the classification picture directly relate to the claimed subject matter, enhancing search precision.
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