Added Matter (6) – Disclaimers

Unlike a positive claim feature, a disclaimer defines what is not covered by a claim. Disclaimers are allowable in principle at the EPO, but only under specific conditions. These conditions depend on the type of disclaimer being used, of which there are essentially three types. These are a) disclosed disclaimers, b) undisclosed disclaimers, and c) disclaimers of positively disclosed features. Each type of disclaimer may bring its own issues for assessing added subject matter.

Disclosed disclaimers are probably the most straightforward in that they are already directly and unambiguously disclosed in the application as filed. For example, the application may claim bikes and the description may explicitly state that the bikes are "preferably not red". This should provide basis to amend the claims to include a disclaimer that the "bike is not red", although care should still be taken that the disclaimed feature is not generalised from its original context (see Added Matter (4) - Intermediate Generalisation here). However, even if they find basis, such disclaimers are considered exceptional and only useable if adding a positive feature to the claim would not define the subject matter more clearly and concisely or would unduly limit the scope of the claim. For this reason, disclosed disclaimers most often appear in chemical or pharmaceutical cases where a chemical structural formula is most clearly and concisely defined as not including a certain substituent, eg "where the halo functional group is not fluorine", rather than trying to define all other possible options.

Undisclosed disclaimers are not disclosed in the application as filed at all. For example, the application may disclose bikes but make no mention of their colour. In this case, a disclaimer that the "bike is not red" is undisclosed, yet may still be allowable without adding subject matter in three limited cases defined by the case law. These are i) restoring novelty over a novelty-only disclosure under Art. 54(3) EPC (a post-published European patent/application, but with an earlier filing/priority date); ii) restoring novelty over an accidental anticipation (a disclosure so unrelated to and remote from the claimed invention that the skilled person would never have taken it into consideration when making the invention - this is often difficult to prove); and iii) removing subject-matter which is excluded from patentability for non-technical reasons (for example a disclaimer that a cosmetic method is "non-therapeutic" to avoid the EPO's exclusion of therapeutic methods from patentability). Undisclosed disclaimers of types i) and iii) are reasonably commonplace, but type ii) is much rarer.

Disclaimers of positively disclosed features sit between the two above extremes, in that the feature is disclosed in the application as filed, but not as a disclaimer. This may be allowable where the application as filed discloses multiple options for non-essential features and the claim is amended to exclude one of the disclosed options with a disclaimer. For example, where the application discloses bikes that are red, green or yellow, a disclaimer may be possible that the "bike is not red". For this type of disclaimer, the test for added subject matter is whether the subject-matter remaining in the claim after the introduction of the disclaimer is, explicitly or implicitly, directly and unambiguously disclosed in the application as filed.

In any of the above situations, the use of disclaimers can be risky, because if they are found unallowable after grant, they cannot typically be removed without broadening the scope of protection, leading to the so-called "inescapable trap" (see Added Matter (2) - The Inescapable Trap here).

This article is a part of our EPO Practice and Peculiarities series. Click here to explore.