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T 3045/19 – Using common general knowledge by an OD without any proof of it boils down to a substantial procedural violation – But BAs did exactly this

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The patent was maintained in amended form by the OD. The proprietor appealed the decision.

For the OD, claim 1 as granted lacked inventive step over specific documents submitted by the opponent.

The proprietor claimed that his right to be heard has been violated on two occurrences:

– he could not dispute the common general knowledge used by the opposition division;

– the OD did not consider his arguments disputing this common general knowledge.

The BA only considered the second objection.

The OD alleged in its decision that

it is commonly known that when a particulate material, such as lignin powder, is used in low amounts as a binder a homogenous distribution of the material is crucial and that such a homogenous distribution is best achieved, when the particles are fine enough. This is immediately evident to the skilled person and as such does not need any pointer at all“.

A similar statement was made in relation to claims 11 and 12.

In its findings of lack of inventive step, the OD used the disputed common general knowledge as a link between the combinations of teachings, within or between documents.

For the BA, the OD made no reference at all to the proprietor’s comments made during the oral proceedings and disputing this common general knowledge. It is not apparent that the proprietor’s arguments on this point were in fact considered by the OD.

For the board, the lack of consideration of the proprietor’s comments amounts to a substantial procedural violation.

The decision was set aside, the file remitted to the opposition division and the appeal fee reimbursed.


The position of the OD using common general knowledge without giving any proof of it reminds of what the boards did in T 2526/19, T 1370/15 and T 1090/12.

In those decisions, T 2526/19 and T 1370/15 in opposition appeal and T 1090/12 in examination appeal, the boards held that not only in ex parte-, but also in inter partes appeal proceedings, a board is allowed to introduce new ex officio common general knowledge without evidence of such knowledge which prejudices maintenance of the patent, to the extent that the board is knowledgeable in the respective technical field from the experience of its members working on cases in this field. 

It is not question of preventing a board of appeal from bringing common general knowledge into the proceedings.

Common general knowledge is in principle never late as it is immanent.

What is worrying is that the boards claim that they do not need to show any evidence in support of such an allegation.

The position taken by the boards in those three decisions contradicts the normal case according to which each party bears the burden of proving the facts it alleges.

In such a situation a board is to be considered as a party as well as a first instance division or parties to first instance proceedings.

It is not acceptable for Boards of Appeal to take liberties they refuse to others and are actually not entitled to.

T 3045/19 makes it clear that this way of doing is not correct, especially when the proprietor contests this common general knowledge.

If a deciding body of the EPO alleges common general knowledge, it has the onus of proof like any other party.

The board should have referred the proprietor’s question to the Enlarged Board of Appeal in T 1370/15

The question should however have been formulated as follows:

“In inter partes proceedings, is the board allowed to introduce new ex officio facts and evidence relating common general knowledge without evidence of such knowledge which prejudice maintenance of the patent?“

This question relates, without any doubt, to a point of law of fundamental importance.

The reference in T 1370/15 to R 20/11 (section 3.1) is biased to say the least.

In R 20/11 the common general knowledge relates to a matter of everyday experience of everyone, which does not require any proof. In this case it was ordering by telephone, which indeed is well known, not only to members of the boards but also by the layman.

In T 2526/19, T 1370/15 and T 1090/12, the knowledge might have been general and common, but it was not in a matter of everyday experience of everyone.

It was in very specific technical domains. This is quite different from the situation in R 20/11.


Art 113(1) / CGK

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5 replies on “T 3045/19 – Using common general knowledge by an OD without any proof of it boils down to a substantial procedural violation – But BAs did exactly this”

Daniel, as you know, on these comment threads I am somewhat of a dilettante, firing off comments without first carefully reading the decisions of the OD and the TBA. So my comment below might be ill-judged. It is just that I like to provoke you into a discussion, from which I can learn about EPO case law faster than myself reading all the decisions.

It seems to me that the case under discussion here is an example of a TBA being pregmatic, seeing what ought to be done, and then cobbling together whatever reasoning is needed to support the conclusion which it has already reached.

Here, I suspect the Board was sceptical whether it is true (never mind “commonly known”) that the finer the particles the more homogeneous their distribution. Personally, I do not see why that should be so. With cookery and metallurgy in mind, I’m thinking that very fine particles might “clump” or otherwise cling together whereas larger particles might be less prone to such phenomena that work against homogeneity. If the OD’s premise is plain wrong, then the case should be remitted to the OD to give the party advocates a proper chance to slug it out against each other, and the Division a second chance to express itself with the necessary precision.

On a wider note, as you point out, there is cgk that everybody knows and there is another category of cgk which is common only within a tiny band of persons of ordinary (or higher) skill in the art but quite unknown to everybody outside that art. The TBA members can be acknowledged to know the first sort of cgk but (however expert the Rapporteur happens to be in the technical field in question) certainly not the second sort.

I guess you agree but have further thoughts on these issues. Let’s hear them, shall we?


Dear Max Drei,

I would not take a comment expressing the gut feeling in view of the decision should be considered as dilettante. It is was it inspires at that moment and it is a reaction worth any more policed one.

If you consider the action of the board vis-à-vis the OD as being pragmatic, it is difficult to agree. The same applies to the three other decisions quoted, as there the boards did not want to really bother about submitting evidence. This does not seem fair towards the proprietor.

I agree with you that there is cgk everybody knows and more field related cgk. In the first category, I would also see a standard computer system and that such a system is considered “notorious” is not disputable. Saying that an item is stable if its centre of gravity is within the projection of its contour on the surface it is standing, is another form of cgk which should not need any proof.

As soon as we go into a more specific area, then the cgk needs to be supported by evidence. And the BA should not be exempted from bringing the proof of what it alleges. In such a situation the BA knew that it wanted to decide on non-patentability. The missing evidence was crucial to the non-patentability and should actually have been supported by proper evidence. The fate of an application/patent cannot depend on the personal technical knowledge of board members.

As far as particles are concerned in general, I would allow myself to say that size certainly plays a role, but other conditions like humidity, surface tension or magnetic attraction may also play a role. As far the particles at stake are concerned, it was daring for the OD to claim what it did and it was correct for the board to sanction it. To be precise, the board did not sanction the lack of evidence, but the fact that the OD did not take into account the arguments of the proprietor in this matter. In the end, the result is the same.

The problem I see more and more with the boards is the absence of a body empowered to check the correct application of the large discretion given to the boards by the RPBA20. This is becoming a fundamental flaw of the EP system.

Daniel, thanks for that reply. It prompts me to ask myself again, whether it is always absolutely essential to have “evidence” in support of an assertion that a particular fact is within the common general knowledge of the skilled addressee. Having one foot in US/UK common law (adversarial) and the other in mainland European civil law (inquisitorial) I see deficiencies (and abuses) in both systems, when it comes to evidence and procedures for finding the facts. Both ways of administering justice can learn from the other. Even more important than the issue what amount of “evidence” is needed is the precious “right to be heard”, and what the Americans call the right to “fair process”. If the OD or the Board relies on its own knowledge for its declaration what is the cgk of the skilled person, it must, for fairness, give the party injured by that declaration a right to contest it, and enough time to put together a reasoned argument why the declaration is not well-founded. After that, a mere denial from the injured party, that what is declared by the Board is NOT cgk is to my mind not enough to deny the Board’s reliance, in the reasoning of its written Decision, on its own declaration what is the cgk. To the contrary, if the injured Party is unable to do better than a mere denial, that alone is evidence in support of the Board’s declaration what is the cgk of the skilled addressee.

This all reads like reversing the burden of proof and, worse, putting on the injured party the burden of proving a negative but, to my mind, sometimes it is appropriate, in the interests of justice, to reverse the burden of proof. I wonder, Daniel, whether you agree.

All that said though, there does seem to be a real problem, how to hold to account a productivity-chasing TBA when it administers justice in a hurry, falling short of fairness (and denying a party its right to due process).


Dear Max Drei,

When a proprietor is confronted with an allegation of prior art at short notice, what can he do?
I would agree that a mere denial would not be sufficient.
But the opportunity to prepare arguments against the allegation of the board should be given.
It is not for the denial that the board considered that the OD did not take into in account the arguments of the proprietor underlying the denial that a SPV was committed.
That should apply also to the boards.
No more, but no less.
Have you ever been successful with an allegation of cgk without an ounce of evidence?
There are situations where a reversal of the proof is acceptable: when facts have been established beyond any reasonable doubt. In any other situation, and certainly not with a mere allegation of a board of what can be cgk. The only exception of what is notoriously known.

If one party brings up “sth. is common general knowledge”, and the OD has reasonable doubt, does the OD also have to ask for prove, if that is not challenged by the other party?

Usually “An assertion that something is common general knowledge need only be backed by documentary evidence (for example, a textbook) if this is contested (see G‑IV, 2).” but must the OD contest the alleged cgk if it has reasonable doubt? And secondly, same question but ending with even if the other party does not contest the alleged cgk.

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