Two part question...

1) Does any one know where I can look up the Canadian Patent Classification Schedule (CPC*)? It stopped being used in 1989, but the old Canadian art (six digit references) is only classified by CPC* and not by IPC. It is a searchable field on the Canadian Patent Office site (CIPO), but I cannot find the schedule there.

2) Does any commercial tool allow searching by Canadian Patent Classification Codes? Here are a few sample docs from 43/76 (rat traps) to see if this field exists in your engine of choice: CA 492931 and CA 479428.

Thanks in advance,



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  1. Hi Dominic

    I can't find it either, but apparently the British Library has it on microfiche

    so I'm guessing there might be something similar in major US libraries, perhaps in book form.

    In my travels I note that it is based upon the USPC so maybe use that as a rough guide.

    I don't know of any commercial databases that have it as a searchable field, and reuse of the acronym by the Cooperative Patent Classification doesn't help.



  2. Hi Domenic,


    have three files I can share with you.  The first is an alphabetical list of the CPC that looks something like this:

    "ABACUS ...........................  235


         Apparatus   .................... 17

         Building   ....................... 20


         Supporters ..................... 2"

    the second is a numeric list of the CPC:




    the third is a detailed schedule of the CPC:



    1/2     . Staple

    1/3     .. For Book or Magazine"

    I am unfamiliar with the WIKI Markup and cannot seem to attach these files for you.  I can email them to you if you send me a personal email here at CIPO; my address is

    On our CIPO website, the Canadian Patent Database is searchable by CPC using the advanced search setting ("").  I don't know of any other tool that is searchable by CPC.

    I hope this helps.


  3. Michael,

    Thank you for sharing this nugget of knowledge! Not something I'll use every day, but when I need it, I know where to find it now. Using the Canadian CPC* is the only way to search hundreds of thousands of expired Canadian Patents that are not classified by IPC and are definitely not text searchable. Hopefully one of the commercial providers incorporates this data, but in the mean time, the Canadian Patent Office retains the monopoly on searching by CPC*.

    I've uploaded all three documents:

    1) The index of classification LINK. This is very similar to the US doc of the same name and points a searcher to the right classification areas based on a one word technology summary.
    2) Class titles LINK. Includes the examiner? in charge of the art and the last revision date.
    3) The complete schedule LINK. It is amazing how similar this schedule is to the US schedule of fifty years ago. Just enough different to make a complete schedule needed.


    P.S. Hopefully we're not having this same conversation in thirty years as we try to track down the US Patent Classification Documents...


  4. Just in case I'm not the only person in the world that ever needs it... I've attached the Canadian Design Registration Classification Scheme (LINK). I love Locarno as much as the next guy, but it's sure nice to slice and dice the data in a different fashion when appropriate.

  5. Dominic,

    I created a searchable online database from the files Michael Matthews provided.  It's at  I'm a computer programmer with an interest in under appreciated patent office data .  I'd be happy to add additional slicing and dicing screens!

    Russ Allen


    1. Russ,

      Be careful about admitting a fondness for historical patent classification schemes or you'll start receiving late night missives from Stephen Adams (Publication List). Yes, I'm sort of kidding.

      Pretty nifty tool you've put together there. A cross-classification search tool is something some of the major patent database providers have incorporated into their offerings to help searchers find the right place in the right scheme. However, no one I'm aware of has done anything with the truly historical schemes like the Canadian system. You'll need to go find all the old National Classification systems to really turn this into giant time suck of a hobby with no hope of a financial reward (smile). Quite a bit of the old art is difficult to find without access to these historical schemes as I discovered with regard to Canadian art a couple of years ago.


  6. Hi Russ,


    That's awesome!  I hope you don't mind, but I passed this on the our examiners here at CIPO; I'm sure they will appreciate it!




    1. Michael,

      Not a problem seeing as you supplied the data!  I've added ipc's and a classification case study to my page.  I'm also working on reloading the cooperative classifications to pick up changes since I loaded it.