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EPO clarifies law relating to disclosed and undisclosed disclaimers

 
EPO clarifies law relating to disclosed and undisclosed disclaimers

20 December 2017

The Enlarged Board of the EPO has cleared away some of the confusion regarding the use of disclaimers (negative features) in claims in decision G1/16, issued this week.  This confirms that disclosed and undisclosed disclaimers are assessed using two separate tests, to be applied in different situations.  The tests set out in G1/03 continue to be the correct approach for assessing the allowability of undisclosed disclaimers whilst G2/10 remains the correct test for disclosed disclaimers.  In particular, the decision confirms that undisclosed disclaimers are still only allowable in very limited circumstances, such as for overcoming a novelty-only citation under Article 54(3) EPC. Here we discuss the decision, and the allowability of disclaimers, in more detail.

The Enlarged Board of Appeal has just handed down its decision G1/16 on disclaimers.  The decision untangles some of the confusion that has surrounded the allowability of disclaimers in recent years, and when they may or may not be considered as “added matter”.

The term “disclaimers” generally refers to negative features which exclude certain subject matter from a claim (e.g., a reference in a claim to “a metal excluding iron”).

In some cases, this negative language is written into the original application during the drafting process, as a proviso.  In this situation, the negative language has literal basis in the application as filed and there will be no problem with added matter.  This situation is not affected by this Enlarged Board decision.

Instead, this decision deals with two other types of disclaimers which were not written into the application at the beginning.

The first are so called “disclosed disclaimers”.  This is the situation where the subject matter excluded from the scope of the claim by amendment was originally described in the application as a possible embodiment of the invention.  That is, a feature that was originally disclosed as a positive feature of the invention is now explicitly disclaimed, as a negative feature.

The second are the “undisclosed disclaimers”.  This is where neither the disclaimer nor the subject matter excluded by it was described in the application as filed.

As an example, consider a claim which is amended during examination to state a casing is made from a metal excluding iron (i.e. disclaiming iron).   This will be a “disclosed disclaimer” if the application as originally filed said that the metal could be any metal such as iron.  (Here, the original positively-described embodiment has been turned into a negative feature.)  It will be an “undisclosed disclaimer” if the application as filed simply said that the casing could be made of metal, without saying anything further.

Case Law Preceding the Enlarged Board Decision

For many years, the test for establishing whether an undisclosed disclaimer could be allowed was considered settled case law, as set out in Enlarged Board Decision G1/03.  This stated that an undisclosed disclaimer would not be considered to add matter, if its purpose was to overcome objections relating to:

(i) novelty-only prior art under Article 54(3) EPC,

(ii) accidental novelty disclosures, or

(iii) excluded subject matter.

The disclaimer must not go beyond what is necessary to overcome the objections and must not introduce clarity issues. It must also not be relevant for assessing inventive step or sufficiency.

More recently, G2/10 considered the situation of disclosed disclaimers.  They reached the conclusion that subject matter disclosed positively could be used negatively in the claim, so as to form a disclaimer.  However, they also said that the subject matter remaining in the claim still had to be, explicitly or implicitly, directly and unambiguously disclosed in the application as filed.  That is, they indicated that the strict standard of the EPO in respect of added matter, sometimes called the “gold standard”, was still to be applied.

Both tests have raised questions.  The test applied by G2/10 seems particularly open to interpretation.

However, following G2/10 some Boards of Appeal have complicated matters still further by suggesting that the “gold standard” test is also to be applied in the case of undisclosed disclaimers.  That is, they have suggested that an undisclosed disclaimer must first meet the criteria set out in G1/03, and then it must be assessed whether what remains in the claim is explicitly or implicitly, directly and unambiguously disclosed in the application as filed.

The referring Board of Appeal in T437/14 pointed out that if this dual test is indeed the correct approach, then undisclosed disclaimers would virtually never be allowable.  In the words of the Board: “If a whole is reduced by an undisclosed first part, the present board fails to see how the remaining second part could ever be regarded as explicitly or implicitly, but directly and unambiguously, disclosed in the application as filed.”

The Enlarged Board Decision

Happily, the Enlarged Board in G1/16 has cleared away some of the confusion by confirming that these are two separate tests, to be applied in different situations.  G1/03 sets out the correct test for undisclosed disclaimers; G2/10 sets out the correct test for disclosed disclaimers.  The Enlarged Board also offered some comments on how the test of G1/03 is to be applied, though these do not seem to significantly change earlier understanding and practice.

In short, then, the decision of the Enlarged Board confirms that undisclosed disclaimers can continue to be permitted in the same limited circumstances as before.  For instance, they remain useful for overcoming a novelty-only citation under Article 54(3) EPC.

However, as before, practitioners and applicants should treat disclaimers with caution.  It should always be considered whether the same objective could be achieved with a “regular” amendment, and what fall-back might be available if the disclaimer is subsequently found to add matter.

Read the commentary from the EPO.