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Copyright (c) 2006 Jan O. Kechel
Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free
Documentation License, Version 1.2 or any later version published by the Free Software Foundation;
with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts.
A link to the license is included at the end of this document.



This HowTo is a step-by-step guide on how you could perform a coordinated search for Prior Art in the Internet.

Patents contain several claims. You have to invalidate each Claim on its own! Just invalidating Claim 1 does not invalidate Claim 2 (but it might still help you there).

We also verified this HowTo ourself with examples on real patents. If you are not sure how some step could be achieved then take a look at our Example Prior Art search


Schecter IBM 03/15/2006 (cited):

I suggest the focus be on finding the closest prior art,
including each and every feature of a claim,
preferably in a single reference.

Basic Steps Before You Start

Identify the patent priority

Each patent has a Priority-Date. This is the day at which the patent was first applied. Only Publications prior to this date can be used against this patent. (One year prior to the filing date is much better.) So first step will always be identifying this date. The Priority-Date can be found on each Patent-Publication. How to Read a Patent

Try to understand the patent - point out the novelty

This (obvious) step is most easily done by summarizing the first patent claim with your own words. To make it even easier your can:

  • Replace unnecessary complex terms with easier ones (e.g. 'client data processing unit' with 'client').
  • Replace complex mathematical descriptions with just a function (e.g. replace 'a = 5*7 + 14 / b^e' with f()).
  • Remove descriptions that do not describe the invention itself but only scientific basics, commercial applications, use-cases or benefits of the invention with nothing (e.g. 'This method is based upon E = mc^2' can be replaced with '-'). This step does not change the invention itself.
  • structure the patent as you understand it.
  • If the invention contains software, try to replace these parts with pseudo-code.
  • Now you should be able to point out the novelty with just one or two short sentences.

Try to find out which kinds of systems might use similar methods

  • This step is really very generally, e.g. if you have a method describing some specific way of copying files from servers to clients, every application doing this can be but into this list (ftp-clients, http-clients, gopher-clients, ways-clients, mail-clients, irc-clients, version control systems, instant-messengers like icq, aim and msn, but also each application that can just copy files in combination with network-filesystems like MS-Explorer, cp, copy, mv, move, xcopy, and also systems that can open files from network-drives like cat, Gimp, Word, OpenOffice, type, etc. could be Prior-Art in this case)
  • We also give you some starting points, depending on the USPTO classification of the patent here: Publication Categorization

Create a list

..with all Programs/Projects that might use similar methods

This actually needs knowledge about the specific programs. You might just try some of the programs (if freely available) to check if they can do what you are looking for. FAQs, Docs or Manuals are also helpful here.

  • Select those that you expect to fit best (maybe assign marks from 1-10) to the described method and write down their download-url / homepages
  • Determine in a first step from which date those (best rated) programs are (e.g. by visiting their Homepages) and mark those that are prior to the Priority Date bold.
  • Eliminate all Projects that are definitely newer than the Priority-Date (and only come back here if you can't find evidence using one of the remaining ones)

Verify selected Projects

Now, that you have a short list of Projects (maybe only one), we need to:

Verify that the implementation / description is older than the Priority-Date

  • Hint
  • You don't need to seek for evidential proof here yet, just write down whichever sources you trust yourself.
  • Take a look to the Documentation-Archive and read about the last Release prior to the Priority-Date
  • Look into the Changelog and try to find the appropriate change.
  • Search the Usenet for this program combined with year-numbers (e.g. 'sendmail 1990', 'sendmail 1989', etc. if the program was sendmail and the priority-date was 1990)
  • Search the mailinglist-archive and find appropriate mails. Try to get the complete mbox including all Headers of the mails)

Verify that it really implemented or described the patent

.. or parts of it, everything is good here!

  • Take a look to the FAQ, Documentation, etc.
  • Ask publicly on the mailinglist of that project

Don't forget to ..

While doing the above you might find other projects on which this project is based upon.

Verify if one of those (even older) Projects already implemented the patented method. If that is the case add it to your list. This is a very normal step, e.g. if you are looking for some graphical methods, you might start with Gimp, and then see that ImageMagick is a program that is havily used by Gimp. Don't forget to checkout ImageMagic as well.

What to do with a specific file that shall be used as Prior Art

If you identified a specific version of a program that holds the Priority-Date and contains parts of the patented method you still need to proof that this file was already publicly accessible at that date:

  • Hint
  • It's not that important that you find hard evidence here. Don't surrender just because you can't find any hard-evidence (as e.g. printed Publications). This will only become important if the patent applicant really questions the publication date. If you e.g. found some electronic timestamps, then mostly the applicant will have to proof that those are bogus.
  • try to find a cvs-archive that contains those files
  • identify complete archives that contain those files (ISO-Images, Linux-Distros, .deb, .rpm, .src.tar.gz, .src.Z, -i386-bin.tar.gz, ..)
  • search for this specific files and try to find proofs for their existance to that date by notating as many download-urls as you can find (according with their local timestamps if available like on ftp-servers)
  • search for (completely different) projects that base upon those files (e.g. cvsgui uses cvs and has a copy of cvs-1.10 in their own version-control cvsgui/cvs-1.10

Tools to aid your search

  • for just about everything, also has a usenet search (google groups)
  • Wikipedia - the free encyclopedia. Articles are very valuable, especially because many of them contain a History-Section and Links to similar projects. Don't forget to check articles in different languages, they often differ very much (use translation-sites). I noticed that german wiki-pages much more often have history-sections than their english equivalents. Look for a translation in 'Deutsch' and checkout if there is a section named 'Geschichte'.
  • Google Scholar provides a simple way to broadly search for scholarly literature. It allows to specify publication-date ranges.
  • Elsevier analogoue to scholar google. Free Scientific Search Portal. Offers earch by year
  • Search Inside Full Text of Nearly All Amazon Books at Once
  • The Internet Engineering Task Force - lots of RFCs (all the Internet Standards)
  • CiteSeer.IST - Scientific Literature Digital Library. Offers a search by year!
  • Citations are very useful to find derivated work from sth. you know. So if you found sth. that contains nearly everything of a patent (as SCCS in the example), then use CiteSeer to find other publications that refer to this one, and look if there is one that mentions the missing part (client/server in the example).
  • waybackmachine - Archives some websites and you can give evidence that sth. was stated on some website at some given date. It has also been reported that this has already been used and holded up on court.
  • This might become a mailinglist where you can ask for assoziations to specific patents. So more people might help you to find appropriate starting-points for your Prior Art research.

Patent Searching

If you are looking for a patent, or want to find a patent that might be used as Prior Art, then you have a good chance here.


  • Esp@cenet - Search engine covering over 60 countries, more than 30 million patents, full text documents along with images (150 million pages). Searches only Abstracts.
  • German Patent Office - English Interface Available - Allows Full Text Searches. Features also Patents in English.

Fee Based

  • - Patents from the USPTO, EPO, WIPO (PCT), Austria, Belgium, Canada, France, Germany, Great Britain, Japan, Spain, and Switzerland, as well as US file histories

Anyway, if you are looking for any Prior Art, then above tools will help you much more. Taking into account that only google itself returns for the letter 'a' 20.470.000.000 results, then the 150 million pages from espacenet and the 240 million pages from the USPTO look like a drop in the ocean.

You might say that USPTO has selected documents and the internet has lots of shit, well, then just say only every 10th internet-page contains some real information, then there are still more then five times as many good documents you can search with google compared to patent search engines (20.470.000.000 / 10 / (150.000.000 + 240.000.000) > 5).

What's next?

Well, if you found some Prior Art, the following options can be considered:

  • The patent is already granted
  1. ask the owner to void the patent himself
  2. ignore the patent and all license fees, if your Prior Art is good, then you don't need to fear beeing sued
  3. try to void the patent by force - sue the owner
  • The patent is not yet granted
  1. send your Prior Art to the inventor, then he has to pass this knowledge on to the USPTO, resulting in a lesser chance that the patent will be granted (for submissions to IBM you can use this form).
  • It's your own patent
  1. don't file it


fun facts

The Patent-Office claims to do all of this for less then 1,000 US$. Assuming that this takes in average about 2 weeks, which are like 60 hours of work, their examiners work for less than 16$ per hour ;-) Kechel 08:54, 14 March 2006 (PST)




osapa/howto_search_for_prior_art_in_the_internet.txt · Last modified: 2016/07/19 01:21 (external edit)