What changes were made to USPTO kind codes in 2001?

In 2001, the USPTO made significant changes to its kind codes system. According to MPEP 901.04(a), several key changes were implemented:

1. Some kind codes were discontinued as of January 2, 2001:
   • Code ‘A’ for Patents was replaced by B1 or B2
   • Code ‘P’ for Plant Patents was replaced by P2 or P3
   • Codes ‘B1, B2, B3…’ for Reexamination Certificates were replaced by C1, C2, C3…
2. New codes were introduced, including:
   • ‘A1’ for Patent Application Publication
   • ‘A2’ for Patent Application Publication (Republication)
   • ‘A9’ for Patent Application Publication (Corrected Publication)
   • ‘B1’ for Patents with no previously published pre-grant publication
   • ‘B2’ for Patents having a previously published pre-grant publication

These changes were made to accommodate the introduction of patent application publications and to better align with international standards.

To learn more:

• USPTO kind codes
• 2001 changes
• patent application publications
• international standards