16 September 2012

The ABCs of Patent Publication

ABC blocksYou have probably noticed the letter/number codes which sometimes appear after patent or application numbers, and if you are not a professional patent attorney or searcher you might have wondered what – if anything – they mean, and whether you should care about them. 

The short answer is that if you care enough to be looking at published patent documents in the first place then, yes, you should care about the codes which appear at the end of the publication numbers.  For one thing, they tell you whether or not the document you are looking at represents a granted patent (i.e. a right that you might potentially infringe) or merely a pending application (which may or may not be granted, now or in the future, in the form you have in front of you). 

To give an example of what we are talking about, Australian patent no. 2007286532 (i.e. Apple’s ‘heuristics patent’, which is among those it is asserting against Samsung in Australia) has been published six times – as AU2007286532-A1, AU2007286532-A8 (twice), AU2007286532-B2, AU2007286532-B8 and AU2007286532-C1.

Since we are sometimes asked by clients what all these added letters and numbers mean, and it is sometimes helpful to know, here is a brief explanation.

THE A’s, B’s AND C’s

The letter codes indicate the stage in the patent’s lifecycle at which it was published.  In summary:
  1. A – a published version of an application which has not yet passed examination;
  2. 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
  3. C – a published version of a patent which has been amended since it originally passed examination.
This system is employed by most patent offices, and you will see that even in jurisdictions in which different numbers are allocated before and after grant, the letter codes still apply.  For example, the full pre-grant publication publication number of a US patent application will be of the form yyyy/nnnnnn-Ax, whereas a corresponding granted patent will have a number of the form n,nnn,nnn-Bx.

We sometimes receive enquiries from clients concerned about a ‘patent’ they have found with very broad claims – perhaps so broad that it seems they could not possibly be valid.  However, if the document is an ‘A’ publication then it is not a patent at all, but an application that has yet to pass examination.  The next steps in a case such as this are to check the current status of the application – perhaps it has since been allowed, and there is a more recent ‘B’ publication, which may include narrowing amendments.  If not, then there are strategies that can be employed to monitor, and perhaps even intervene in, the examination process.


In many jurisdictions, there may be an additional digit following the letter ‘A’, ‘B’ or ‘C’).  There may be differences in how these digits are interpreted, depending upon the exact examination and granting process which occurs in each country.  The following information is valid for the Australian publication system.

If the digit is a ‘1’, then you are looking at the first publication in a particular case.  For example, an ‘A1’ document is the first publication of an application, which usually occurs at around 18 months from the earliest filing date.  A ‘B1’ publication occurs if the application passes examination before being published as an ‘A1’ document (i.e. in less than 18 months from the initial filing).  However, if the application was previously published, then the republication at acceptance will be designated ‘B2’.
The ‘B1’ or ‘B2’ publication will include any amendments which were made to the application as a result of the examination process.

If the application is amended again after acceptance (e.g. as the result of opposition proceedings), or after grant (e.g. under section 104 or section 105 of the Patents Act 1990), then the corresponding republication will be designated ‘C2’.
Innovation Patents
The above discussion of ‘A1’, ‘A2’, ‘B1’ and ‘B2’ publications applies when the application or patent in question is a standard patent.  If it is an innovation patent, then a different scheme applies.

As you may be aware, innovation patents are granted and published very quickly after filing (typically within one month).  However, at this stage they have not been examined to determine their validity, and they are therefore not enforceable.  For this reason, the first publication is considered to be an ‘A’ document, even though a patent is technically granted.

A granted innovation patent is designated ‘A4’.  If an innovation patent application happened to be published before grant (which would be unusual, but is theoretically possible), it would be designated ‘A5’.  An innovation patent which is amended after grant, but prior to any examination which may occur, is designated ‘A6’.

Examination of an innovation patent is optional, but if the patentee requests examination, and the patent passes and is certified, it is republished as a ‘B4’ document.  If the patent is amended again after certification, then it is republished with a ‘C4’ designation.
If, rather than being amended (e.g. to change the substantive scope of the claims) an application or patent is corrected (e.g. to rectify an error or omission) then the digit allocation will be an ‘8’ or a ‘9’.

An ‘8’ means that only the bibliographic data has been corrected and republished, i.e. the basic information about the application or patent, such as its filing date, priority date and any prior applications from which priority is claimed, ownership details, inventor details, and so forth. For an ‘8’ publication (e.g. an ‘A8’, ‘B8’ or ‘C8’) the patent specification, claims and drawings will be unchanged from the previously-published version.

A ‘9’ means that the complete patent document has been republished, i.e. including the specification, claims and drawings.
In summary:
  1. ‘1’ and ‘2’ publications are standard patents and applications;
  2. ‘4’, ‘5’ and ‘6’ publications are innovation patents; and
  3. ‘8’ and ‘9’ publications are corrected standard or innovation patents/applications.


As noted above, Apple’s Australian ‘heuristics’ patent no. 2007286532 has been published six times.  These publications are:
  1. A1 – first application publication, on 3 April 2008;
  2. A8 – correction of missing priority claims, published 5 March 2009;
  3. A8 – correction of missing international publication no. WO2008/030976, and to add missing inventor Steven P Jobs, published 22 October 2009;
  4. B2 – publication at acceptance, on 6 August 2009 (application amended compared to ‘A’ publications);
  5. B8 – incorporating all A8 corrections, published 22 October 2009; and
  6. C1 – publication on 27 May 2010 of narrowing amendments requested by Apple.
For interested readers, shown below is the marked-up copy of claim 1, as amended by Apple after grant of the patent.  We presume that Apple considered this amendment to be necessary, perhaps in view of some additional prior art of which it had become aware.  Certainly, the fact that it made the amendment promptly  (i.e. not long after grant of the patent) indicates the importance Apple placed upon ensuring that its Australian patents were maintained in good order, just in case it ever needed to enforce them!

Apple heuristics claim 1


The seemingly innocuous, and somewhat cryptic, codes appearing after the patent or application number in a published specification are a useful guide to the status of the document.

It is therefore worth being at least passingly familiar with these codes if you are at all in the habit of reading patent publications!

IP Australia has a brief summary of its implementation of these ‘document kind codes’ on its own website.

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