Kind code

In patent law, a kind code, or WIPO Standard ST.16 code, is a code used on patent documents published by intellectual property offices to distinguish different kinds of patent documents.^[1][2] A kind code includes a letter, and in many cases a number, used to distinguish the kind of patent document (e.g., publication of an application for a utility patent (patent application publication), patent, plant patent application publication, plant patent, or design patent) and the level of publication (e.g., first publication, second publication, or corrected publication).^[1] The recommended use is the two-letter country code followed by the patent document number and then the kind code, e.g., "US 7,654,321 B1" for U.S. Patent No. 7,654,321 where there was no previously-published patent application publication, and "US 2003/1234567 A1" for U.S. Patent Application Publication No. 2003/1234567, published in 2003.^[1]

The European Patent Office (EPO) uses kind codes such as the following. Kind codes for patent applications begin with A and include

• A1, for an application published with a European search report;
• A2, for an application published without a European search report; and
• A3, for a later publication of the European search report.^[3]

Kind codes for granted patents begin with B and chiefly include B1 for a European patent specification (granted patent).^[3]

The Japan Patent Office (JPO) uses kind codes including

• A for publications of patent applications; and
• B1 and B2 for publications of granted patents.^[4]

In the United States, effective January 2, 2001, the kind codes indicate a variety of documents published by the United States Patent and Trademark Office (USPTO), most importantly patent application publications and patents. The kind codes include

• A1, for a patent application publication (pre-grant publication);
• B1, for a patent issuing from an application that was not previously published as a pre-grant publication; and
• B2, for a patent issuing from an application that was previously published as a pre-grant publication.^[1]

Before January 2, 2001, the kind code for issued patents was A.^[1]

For publications of international patent applications filed under the Patent Cooperation Treaty, the kind codes include

• A1 for an application published with an international search report (ISR);
• A2 for an application published without an ISR; and
• A3 for later publication of the ISR.^[5]

•  This article incorporates public domain material from websites or documents of the United States Government.