How are Inter Partes Reexamination Certificates numbered?
Inter Partes Reexamination Certificates are numbered using a specific system. According to MPEP 2690:
“The inter partes reexamination certificates will be numbered in a separate and new ordinal sequence, beginning with “(1st)”. The certificate number will always be the patent number of the original patent followed by a two-character “kind code” suffix. The “kind code” suffix is C1 for a first reexamination certificate, C2 for a second reexamination certificate for the same patent, etc.”
This numbering system allows for easy identification of the reexamination history of a patent.
To learn more:
Topics:
MPEP 2600 - Optional Inter Partes Reexamination,
MPEP 2690 - Format Of Inter Partes Reexamination Certificate,
Patent Law,
Patent Procedure