WHAT DO THE LETTERS & NUMBERS AT THE END OF A PATENT PUBLICATION DENOTE?

Most often we see patent numbers ending with letters A B or C.  These letters carry a specific meaning.  These letter codes indicate the stage in the patent’s lifecycle.  The additional digit following the letter ‘A’, ‘B’ or ‘C’ carries extra information, but depends upon the exact examination and granting process which occurs in each country.

o   A – a published version of an application which has not yet passed examination;

Therefore if the document is an ‘A’ publication then it is not a patent at all, but an application that has yet to pass examination.

§  A1 document is the first publication of an application, which usually occurs at around 18 months from initial filing.

§  A2 document is second or subsequent publication of application, requested by applicant.

§  A9 document is the publication with correction of errors in either A1 or A2.

o   B – a published version of an application or patent which has passed examination, i.e. which is either a granted patent, or an accepted/allowed application; and

§  B1 document is a granted patent.  This document is not published as patent application earlier. That means after initial filing it was directly granted patent.

§  B2 document is a granted patent which was earlier published as patent application.

o   C – a published version of a patent which has been amended since it originally passed examination.

Therefore, for a pre-granted patent publication i.e. a patent application – publication number appears something in this form --- yyyy/nnnnnn-Ax

Whereas a corresponding granted patent will have a number of this form --- n,nnn,nnn-Bx

For more information, please see below links,

http://blog.patentology.com.au/2012/09/the-abcs-of-patent-publication.html; 

http://www.bios.net/daisy/patentlens/2354.html

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