What are the kind codes for U.S. patent publications?
U.S. patent publications use specific kind codes to indicate the type and status of a document. According to MPEP 901.04(a):
- A1: Patent Application Publication
- A2: Republished Patent Application Publication
- A9: Corrected Patent Application Publication
- B1: Utility Patent
- B2: Utility Patent (issued after reexamination)
- C1, C2, C3, etc.: Reexamination Certificate
- E1: Reissue Patent
- H1: Statutory Invention Registration (SIR)
- P1: Plant Patent
- S1: Design Patent
These codes help identify the specific type and status of a U.S. patent document at a glance.
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