WIPO Standard ST.6 Publication Number Formatting

Historically, a patent document could be uniquely identified by the country code, the publication number, and the kind code.  However, as the need for related corrected documents becomes more popular, the combination of these three codes are no longer necessarily unique, and the date of publication is also included to distinguish each.

Patent applications filed with an intellectual property office are first given an application number upon initial filing. Subsequently, one or more related documents may be published: either the application as filed or based upon the application (e.g., an examined application or a granted patent).  A patent is typically published 18 months after the application filing date.

WIPO Standard ST. 6 has recommendations for the format of a publication number.  It suggests that, as for the application number format, the country code at the start, and the kind code at the end, are not officially part of the publication number. However, to completely identify a patent publication, these must be associated alongside the number and publication date.  Read on to find out the WIPO recommendations for the number part of the publication number.

Recommended Publication Number Format


An identifier is commonly added to the front of an application number to designate the type of IP right or regional office. For example designs may have a different identifier than patents, and/or applications filed in one city may have a different identifier to those filed in another city under the same system.

Year Designation

The publication year, according to the Gregorian calendar, consists of 4 digits YYYY.

Serial Number

A fixed length of 7 digits for the serial number is preferable.  It is suggested that an increasing numerical sequence is used within a given year/time period, i.e. starting at 1000000 in the period 2000-2005.

The serial number should be the same as the application number for a single application number.  If there is more than one type of IP (e.g. patent, design) then the same publication number should be used no more than once.  Also, if an application spawns additional applications, the additional ones are considered as separate.


Separators such as a slash “/”, a hyphen “-”, or a space ” ” are regularly used between the identifier, year and serial number.  Also, within the serial number, this may be further separated by commas “,”, full stops “.” or spaces ” “.


At present, although WIPO wish for the Standard ST. 6  to be adopted worldwide, various states still use their own ways of displaying the publication number, based on a numbering tradition in their IP offices.  Although not as widespread as the variations in application number formatting, it is still advisable to get yourself familiar with the different publication number styles – just go to Variations of Publication Number Formatting by Country.