How have Kind Codes changed for U.S. patent documents since 2001?
The United States Patent and Trademark Office (USPTO) began using WIPO Standard ST.16 codes (Kind Codes) on January 2, 2001. This change brought about several modifications to the coding system:
- New codes were introduced for patent application publications (A1, A2, A9)
- Codes for granted patents were changed (B1, B2)
- Specific codes were assigned to plant patents and their applications (P1, P2, P3, P4, P9)
- Reexamination certificate codes were updated (C1, C2, C3, …)
The MPEP provides a detailed table of these changes, stating: “It is recommended that USPTO documents be identified by the following three elements: (A) the two-character country code (US for United States of America); (B) the patent or publication number; and (C) the WIPO ST.16 kind code.”
These changes were implemented to improve the clarity and consistency of patent document identification across different types of patents and publications.
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