Kind Codes are used to identify the type of patent publication - the kind of document. Kind Codes appear on the printed document or on the PDF to the right of the patent number. Understanding the Kind Code can help you understand the history of the patent. For example, a patent with a B1 Kind Code was not published when it was a patent application. A patent with Kind Code of B2 was published as an application. The Kind Code B1 in the example below indicates a patent where the application wasn't published after 18 months after the Pre-Grant Publication process as USPTO - Patent: Not Previously Published.
The list is supposed to be a standardized list adopted by most of the globe's patent offices but like most things in the patentsphere there are many variations. We have gathered the most current list of US Kind Codes used by the USPTO along with links to the two different lists that they publish that contain the data.
Just to give you a feel for the art and science of the Kind Code, here's link to one provided by the American Chemical Society:
http://www.cas.org/content/references/patkind
Here's another from the European Patent Office:
https://register.epo.org/espacenet/help?topic=kindcodes
And if you are really ambitious and want to explore all the global schemes and how they have changed over time, here is a link to the 101 page version from the Handbook on Industrial Property Information and Documentation from the World Intellectual Patent Organization (WIPO - pronounced Why-Poe if you want to sound like a patent cognoscenti.)
http://www.wipo.int/standards/en/pdf/07-03-02.pdf
As you can see from the list, Kind Codes are fluid just like everything else in the patentsphere.
Way Better Patents has a variety of patent information tools designed to make information about patents more accessible and easier to understand. From time to time we post updates on these tools here.
