Decision G 1/15 by the Enlarged Board of Appeal on partial priority – Consequences, Implications and Possible Problems

Dr. G. Krobath (DE), European and German Patent Attorney

Overview

In the first section, the decision G 1/15 of the Enlarged Board of Appeal on partial priority and the background of the decision will be presented. In the second section, consequences, implications and possible problems resulting from this decision will be discussed.

I. The Decision G1/15

I.1 Background

The basic question which laid the ground for the decision G 1/15 of the Enlarged Board of Appeal is:

Can a claim encompassing a generic term (so-called generic “OR”-claim) which can validly claim priority only for a subset of the generic term be divided into two parts, a first part claiming the priority validly and a remaining second part not claiming the priority validly?

In the earlier decision G 2/98 of the Enlarged Board of Appeal, it was stated (Reasons point 6.7, last sentence) that:

“The use of a generic term or formula in a claim for which multiple priorities are claimed in accordance with Article 88(2), second sentence, EPC is perfectly acceptable under Articles 87(1) and 88(3) EPC, provided that it gives rise to the claiming of a limited number of clearly defined alternative subject-matters.” (emphasis not included in the original decision)

Thus, after the decision G 2/98, the question for determining if a partial priority of a generic “OR”-claim is valid was: what is a “limited number of clearly defined alternative subject-matters”?

E.g., if the specific term is “Helium” and the generic term is “noble gases”, it seems clear that partial priority for the generic “OR”-claim is valid according to the decision G 2/98, since noble gases comprise “a limited number of clearly defined alternative subject-matters”, since there are only six noble gases in nature, i.e., a limited number, and each of them is a clearly defined alternative.

However, if a first priority application discloses a subject-matter comprising bronze and a later application claims a subject-matter comprising metal alloys, the priority is probably not valid according to the wording of the decision G 2/98 since the number of metal alloys is neither limited nor are the metal alloys clearly defined alternatives.

I.2 Toxic Divisional Application

One problem before the decision G 1/15 was the so-called „toxic divisional application“. An applicant files a first non-European priority application concerning subject-matter X and then later files a second European patent application claiming subject-matter Y, wherein X is subset of Y, and subject-matter X, and claims the priority of the first application. Then, the applicant files a European divisional application based on the second application and shifts all content concerning X in the divisional application while leaving only disclosure concerning Y (without explicitly naming X, e.g., as an example) in the second application.

Now, the priority date of the divisional application is the date of filing of the first application (since it claims the priority of the first application validly) and the priority date of the second application is the date of filing of the second application (since Y cannot validly claim the priority of the first application disclosing only X unless Y encompasses “a limited number of clearly defined alternative subject-matters”; according to the general view before the decision G 1/15), wherein the date of filing of the second application lies after the date of filing of the first application.

Since the divisional application has an earlier priority date than the second application, the divisional application is state of the art according to Art. 54 (3) EPC for the second application (assuming that the divisional application will be published). Since the general is not novel over the specific, the claimed subject-matter Y in the second application is not novel over the divisional application, which discloses X. Thus, by filing a divisional application, one application by the applicant (divisional application disclosing X) prevents the applicant from getting a patent for a second application with a more generic claim (second application claiming Y).

I.3 Overview of the decision G 1/15

The Enlarged Board of Appeal decided in the decision G 1/15:

“Under the EPC, entitlement to partial priority may not be refused for a claim encompassing alternative subject-matter by virtue of one or more generic expressions or otherwise (generic “OR”-claim) provided that said alternative subject-matter has been disclosed for the first time, directly, or at least implicitly, unambiguously and in an enabling manner in the priority document. No other substantive conditions or limitations apply in this respect.”

Furthermore, the Enlarged Board of Appeal stated in Reasons point 5.3 of the decision G 1/15:

“As a consequence, the proviso laid down in G 2/98, (supra, Reasons point 6.7, last sentence), cannot be construed as implying a further limitation of the right of priority.”

Hence, the statement “provided that it gives rise to the claiming of a limited number of clearly defined alternative subject-matters” in the decision G 2/98 is no condition for a partial priority to be valid, but rather a nullum.

II. Consequences, Implications and Possible Problems

The decision G 1/15 by the Enlarged Board of Appeal has many consequences. Firstly, no toxic divisional applications are existing anymore, since the subject-matter of the later application, which claims priority of a priority application, is de facto divided in two parts, a first part which is disclosed in the priority application and which claims the priority validly and a remaining second part which is not disclosed in the priority document and which does not claim the priority validly, wherein the second part is in principle novel over the first part.

Hence, in the situation discussed in section I.2, the first part of Y, which comprises X, claims the priority validly and the remaining second part of Y (i.e., Y without X) does not claim the priority validly but is novel over X, in principle.

For further discussions of the decision G 1/15, let us take a look at the following Example 1:

A first application discloses a temperature range of 10 °C – 20 °C and a later second application claims a temperature range of 10 °C – 30 °C, wherein the second application claims the priority of the first application[1].

According to the decision G 1/15, the range claimed in the second application is de facto divided in a range 10 °C – 20 °C, which claims the priority validly, and in a range of >20 °C – 30 °C, which does not claim the priority validly, but which is (mathematically) novel over the range 10 °C – 20 °C.
However, there are several problems arising out of the decision G 1/15.

II.1 Unequal Treatment of Applicants

One problem caused by the decision G 1/15 is that a first applicant submitting an application claiming subject-matter Y and a second applicant submitting an application claiming subject-matter Y are treated differently concerning Y if the first applicant can claim a priority for subject-matter X (wherein X is a subset of Y), which was disclosed in an earlier priority application.

This aspect is discussed in detail in the following on the basis of Example 2:

Applicant A1 files a first application disclosing subject-matter X and later files a second application claiming Y, wherein X is a subset of Y, and claims the priority of the first application. Applicant A2 files an application claiming Y, on the same day on which applicant A1 files the second application.

Applicant A1 has no problem claiming Y, since Y according to the decision G 1/15 is de facto conceptually divided in X (which claims the priority validly) and Y without X (which does not claim the priority validly but which is novel over X, in principle).

Applicant A2 does not get a patent which claims Y, since the part of the second application of applicant A1 concerning X is state of the art according to Art. 54 (3) EPC for the application of applicant A2. Hence, the claimed subject-matter Y in the application of applicant A2 is not novel over X, which is disclosed in the application of applicant A1. Applicant A2 has to draft an undisclosed disclaimer to exclude X from the subject-matter Y, so that the claimed subject-matter in the application is novel.

However, there are very stringent rules for an undisclosed disclaimer which does not violate Art. 123 (2) EPC (cf. the recent decision G 1/16 by the Enlarged Board of Appeal of December 2017). The undisclosed disclaimer may only exclude as much as is necessary for the remaining subject-matter claimed to be novel over the disclosure of the earlier document according to Art. 54 (3) EPC. If more than this is excluded by the undisclosed disclaimer, the disclaimer is a violation of Art. 123 (2) EPC and not allowable. If the undisclosed disclaimer is part of the issued patent, the applicant is caught in the Art. 123 (2) EPC / Art. 123 (3) EPC trap.

The rules for an undisclosed disclaimer are even more stringent if an explicitly disclosed embodiment is excluded by the disclaimer (e.g., applicant A2 has included an explicit embodiment in the form of X in the application).

Thus, applicant A2 has to formulate an undisclosed disclaimer with due care. If the disclaimer is too broad, the disclaimer is an inadmissible extension according to Art. 123 (2) EPC, and if the disclaimer is too narrow, the claimed subject-matter is not novel. Further, applicant A2 is always in danger of the disclaimer subsequently (after the issue of the patent) being deemed to be too broad and the patent being lost due to Art. 123 (2) and (3) EPC.

One could argue that this unequal treatment of applicant A1 and applicant A2 is appropriate since applicant A1 filed a first application with subject-matter X before and applicant A2 did not. However, this priority application for the subject-matter X should have no implications for the subject-matter Y without X, since these two subject-matters are two distinct inventions, wherein one subject-matter is novel over the other subject-matter by definition. An application with a claim encompassing the second subject-matter Y without X was submitted to the European Patent Office by each of the two applicants on the same day. Hence, for this subject-matter Y without X, there should be an equal treatment of applicant A1 and applicant A2.

If the Enlarged Board of Appeal had made a different decision in G 1/15, e.g., if it had decided that there is no partial priority in such a case or only in very limited cases, applicant A1 would have had to file the second application with an explicit OR-claim, i.e., claiming “Y without X or X”, or draft an undisclosed disclaimer later, too. In this case, the disclaimer drafted by applicant A1 has to exclude (at least) X from Y, i.e., applicant A1 is in a very similar situation as applicant A2 who has to draft an undisclosed disclaimer excluding only X from Y.

However, with the decision G 1/15 as it is, there seems to be an unequal treatment of applicant A1 and applicant A2 concerning the subject-matter Y (without X), since applicant A2 has to draft an undisclosed disclaimer and is in danger of losing his patent while applicant A1 is not in this danger.

II.2 Determining the Priority Date of a Specific Subject-Matter Can Be Difficult

The determining of the priority date for a specific subject-matter can be difficult after the decision G 1/15. Before the decision G 1/15, the situation was clearer since the priority was only valid in connection with ranges if the same exact range was claimed in the later application which was disclosed in the earlier application. Now, according to the decision G 1/15, ranges can de facto conceptually be divided into many different subranges without any of the subranges having to be explicitly claimed in the later application. Thus, the number of subranges can in principle be unlimited, since the number of priority applications of which priority is claimed by an application is unlimited.

The determining of the priority date can become even more difficult, e.g., if the subject-matter is an alloy comprising ten or fifty different compounds.

The Enlarged Board of Appeal has considered this problem in the decision, but stated in Reasons point 6.6 of the decision G 1/15 concisely:

“The task of determining what is the relevant disclosure of the priority document taken as a whole, and whether that subject-matter is encompassed by the claim in the subsequent application, is common practice in the EPO and among practitioners of the European patent system and as such should not pose any additional difficulty. Nor does it create uncertainty for third parties, as argued by the respondent and in some amicus curiae briefs. Although it can be a demanding intellectual exercise, the decisions reached in cases T 665/00, T 135/01, T 571/10 and T 1222/11 all show that it can be carried out without any need for additional tests or steps.”

However, e.g., in the case of ten priority documents and an alloy comprising ten different compounds, wherein the priority documents encompass many different ranges, respectively, the task of determining the priority date of a specific alloy can be more than a demanding intellectual exercise; it can create legal uncertainty.

This applies even more to the following Example 3, also briefly mentioned in the decision G 1/15:

The first application discloses a subject-matter with a value of “ca. ½” while the later second application claims a subject-matter with the range of “¼ to ¾” claiming the priority of the first application.

According to the decision G 1/15, the range “¼ to ¾” is de facto conceptually divided into the subrange “¼ up to ca. ½” claiming the priority not validly, the value “ca. ½” claiming the priority validly and the subrange “larger than ca. ½ to ¾” claiming the priority not validly.

Several problems arise from this de facto dividing of the range into several subranges: is the priority date of the subject-matter with the value “0.55” the date of filing of the first application or of the second application; i.e., is the value “0.55” still covered by “ca. ½” or does the value “0.55” lie in the range “larger than ca. ½ to ¾”, wherein the range “larger than ca. ½ to ¾” cannot claim the priority validly?

How far the value “ca. ½” extends is unclear and creates legal uncertainty. Before the decision G 1/15, the priority would not have been valid (according to general view) since the value “ca. ½” is not explicitly claimed in the subject-matter of the later application and, thus, the priority date of the subject-matter with the value “0.55” would have been the date of filing of the later second application.

II.3 Margin of Uncertainty/Error Margin

One further consequence of the decision G 1/15 is – as discussed above – that a range which is claimed in a later application, wherein the later application claims the priority of an earlier application, is de facto divided into subranges which do not have to be explicitly claimed in the later application. The subranges of the larger range, wherein one subrange claims the priority validly and the other subrange does not claim the priority validly, are immediately adjacent to each other, i.e., for moving from one subrange to the immediate adjacent subrange only an infinitesimal change of the respective value is necessary.

Let us take another look at Example 1, wherein the range disclosed in the first priority application is 10 °C – 20 °C and the later second application, which claims priority of the first application, claims the range 10 °C – 30 °C. According to the decision G 1/15, the subrange 10 °C – 20 °C claims the priority validly, while the subrange >20 °C – 30 °C does not claim the priority validly but is (mathematically) novel over the range 10 °C – 20 °C.

However, every physical value has a margin of uncertainty or error margin. Does the range up to 20 °C (i.e., including exactly 20 °C) not also include a value above 20 °C due to the margin of uncertainty/error margin and is the subrange starting exactly above 20 °C novel over the range ending at 20 °C?

There is at least one decision of the Boards of Appeal discussing this aspect, viz T 0594/01. The relevant discussion can be found in Reasons points 4.1.5 to 4.1.7 (emphases not in the original):

“4.1.5. Furthermore, although the Board concurs with the Appellant that only an unambiguous disclosure may be considered in assessing novelty, it remains the case that any technical information is addressed to a skilled reader. In that context, it must be pointed out that it is common general knowledge, as shown by document (10) on page 46, that every experimental measurement in quantitative analytical chemistry as well as any result of any physical measurement cannot be dissociated from the margin of uncertainty attached to the measurement. Normally, the uncertainty of a measured experimental value is irrelevant for the assessment of novelty. However, when a specific experimental value is disclosed in an example of the prior art, seeking to distinguish the claimed subject-matter therefrom only in terms of an upper limit required to be "lower than" the experimental value must fail as the claimed subject-matter is still not distinguishable from the prior art within the margin of experimental error.

4.1.6. Therefore, the carbon dioxide concentration range defined in Claim 1 of each request, i.e. lower than 0.1 wt%, does not distinguish it from the experimental carbon dioxide concentration value, i.e. 0.1 wt%, disclosed in Example No. 4 of document (1).

4.1.7. For these reasons, the subject-matter of Claim 1 of the main and first auxiliary requests lacks novelty in view of document (1).”

Thus, according to this decision, the range lower than 0.1 wt% does not distinguish itself from the physical value 0.1 wt% and is not novel over the value 0.1 wt%.

Hence, when the later second application claims the range of 10 °C – 30 °C, how does the range >20 °C – 30 °C distinguish itself from the value 20 °C, which is disclosed in the first priority application as an end value of the subrange? The value 20 °C as an end value of the range 10 °C – 20 °C is not “a specific experimental value” as in the case of the decision T 0594/01, but every experimental measurement and, hence, every physical value has a margin of uncertainty.

Furthermore, when a value is given as 20 °C, it comprises the values from 19.5 °C to 20.4 °C (due to the normal rules of error margins/rounding according to the Guidelines for Examination in the European Patent Office section G-VI 8.1). Hence, the question arises if the range 10 °C – 20 °C also comprises values up to 20.4 °C and one wonders how a range >20 °C to 30 °C can be novel over a range/value which includes 20.4 °C?

The “test” for determining what is disclosed in an application concerning priority is the same “test” as for determining novelty (cf. the decisions G 1/03 and G 2/10). Hence, usually, when a subject-matter is not novel over a document, the subject-matter can claim the priority validly.

If the range starting at >20 °C does not distinguish itself from the value 20 °C (cf. the decision T 0594/01 cited above) and, thus, is not novel over 20 °C, can a part of the range >20 °C validly claim the priority and if so up to what value? What is the situation if the temperature of 20 °C is given as a “specific experimental value“ in the priority document?

So, in Example 1, when the value 20 °C is disclosed as “a specific experimental value” the question is: is the border which divides the claimed range 10 °C – 30 °C into two subranges, wherein one subrange on one side of the border claims the priority validly and the other subrange on the other side of the border does not claim the priority validly according to the decision G 1/15, at 20.4 °C, since the value 20 °C comprises values from 19.5 °C to 20.4 °C (according to normal rounding rules and the Guidelines for Examination in the European Patent Office section G-VI 8.1)? Or is the value dividing the two subranges even higher than 20.4 °C?

Does not the same problem pose itself at this border of 20.4 °C? I.e., if 20.4 °C as an end value is disclosed in the first priority application, does the range starting at larger than 20.4 °C distinguish itself from the value 20.4 °C of the first priority application due to margin of uncertainty in view of the decision T 0594/01 cited above?

In particular, what is the situation if the first priority application discloses 20.4 °C as a “specific experimental value”?

Wherever one puts the border between the subrange of a larger range which claims the priority validly and the subrange of the larger range which does not claim the priority validly, the difference between the two subranges is infinitesimal, and, thus, it raises the question if the one subrange distinguishes itself from the end value of the other subrange, i.e., if the one subrange is novel over the other subrange, considering the ever existing margin of uncertainty of every physical value.

This problem is enhanced since –typically– a specific way to measure temperature does not have to be disclosed in the application to enable the subject-matter to be carried out by the person skilled in the art. However, a temperature of 20.4000 °C measured with one method (e.g., an alcohol thermometer), i.e., a value within the range 10 °C – 20 °C of the first priority application (considering the rules of rounding according to the Guidelines for Examination in the European Patent Office section G-VI 8.1), may be measured to be 20.4001 °C with another method (e.g., an infrared measuring device), i.e., a value larger than 20 °C and in the range “>20 °C to 30 °C” (even when considering the rules of rounding according to the Guidelines for Examination in the European Patent Office section G-VI 8.1) and, thus, not within the range claiming the priority validly. Hence, a value given as 20 °C can be within the range claiming the priority validly with one measuring method and outside of the range claiming the priority validly with another measuring method.

So, the question remains: where is the border which divides a range into two subranges, wherein one subrange claims the priority validly while the other subrange does not claim the priority validly? And, does the one subrange distinguish itself from the other subrange when considering the error margin?

In the decision G 1/15, the Enlarged Board of Appeal has not considered the rules of rounding nor the ever existing margin of uncertainty of physical values, at least the decision does not address any of the subjects.

These problems can cause legal uncertainty, since determining the priority date of a subject-matter with a specific value can be relevant in determining if a specific publication is state of the art for a specific value of a range claimed in the later application.

III. Summary

The decision G 1/15 has “solved” the problem of toxic divisional applications by allowing partial priority without requiring explicit claiming but has created some new problems. These new problems can lead to an unequal treatment of applicants and can cause legal uncertainty in determining the priority date of a specific subject-matter. It remains to be seen if causing the problems outlined in this article and the corresponding legal uncertainties outweigh the benefits of the “extinction” of toxic divisional applications.

1. In this article, the subject-matters of the priority application and the later application are always the same except for the differences explicitly mentioned herein