Under Article 123(2) of the European Patent Convention (EPC), a European patent application may not be amended in such a way that it contains subject matter which extends beyond the content of the application as filed.

The intention of Article 123(2) EPC is that an applicant (of a European patent application) should not be allowed to improve their position by adding subject matter not disclosed in the application as filed. Allowing non-disclosed subject matter to be added to the patent application post-filing, would provide the applicant an unwarranted advantage and could be damaging to the legal security of third parties relying on the contents of the application as filed.

As European patent attorneys – and general EPC enthusiasts – are only too aware, the European Patent Office (EPO) takes a very strict approach to the assessment of so called “added matter”. While it is not a requirement that any claim language has verbatim support in the application as filed, absence of such support may result in objections being raised against the allowability of a claim amendment under Article 123(2) EPC. This strict approach to added matter is exemplified by a couple of recent decisions from the EPO’s Boards of Appeal, in which the absence of a mere comma(s) from a claim was deemed to result in the claimed subject matter extending beyond the content of the application as filed – and therefore contravening Article 123(2) EPC. In both instances the deficiency could not be rectified by amendment and so the patents were revoked.

T 1127/16 (Aircraft communication method/BOEING) of 18.2.2021

This case concerned a patent proprietor’s appeal against the decision of the Opposition Division to revoke a contested European patent (EP1798872) relating to a method for handling aircraft communications.

Claim 1 of the Main Request (claim 1 as granted) recited:

"A method for handling aircraft communications, comprising:

…

(g) evaluating a preference to determine a preferred network of the plurality of transmission networks, wherein the preference comprises a preference list identifying a selection of the plurality of broadcast networks in order of preference and identifying the highest in preference of the plurality of broadcast networks in the preference list that is available;

…”

Feature (g) contains three sub-features:

• evaluating a preference to determine a preferred network of the plurality of transmission networks
• wherein the preference comprises a preference list identifying a selection of the plurality of broadcast networks in order of preference
• and identifying the highest in preference of the plurality of broadcast networks in the preference list that is available

While sub-features (i) and (ii) are separated by a comma; sub-features (ii) and (iii) are not and therefore are in the same clause and the Board ruled that they must consequently be read together, i.e., a preference list comprises information "identifying a selection of the broadcast networks in order of preference” and information “identifying the highest in preference of the plurality of broadcast networks in the preference list that is available”. This feature was not disclosed in the application as filed.

The Reasons for the Decision indicated that a comma would be necessary to separate feature (iii) from feature (ii) in order to suggest that each occurrence of the word "identifying" should be interpreted differently by the reader. In particular, the Board noted that “It cannot however be expected that the skilled person reading a claim would speculate as to other possible meanings which might result from inserting commas at various places”.

In respect of whether the description and the drawings should be taken into account when interpreting a claim, the Board followed established case-law that “a claim should essentially be read and interpreted on its own merits” (see e.g. T 1279/04, T 1404/05, T 1018/02, and T 197/10) and stated “the claim including this feature made technical sense so that there was no requirement to resolve any ambiguity by consulting the description and drawings of the application as filed”.

In particular the Board noted “the fact that a claim of a patent is to be construed by a mind willing to understand and not a mind desirous of misunderstanding does not mean that the description and the drawings of the patent have automatically to be consulted as soon as an "ambiguous" feature (i.e. a feature which at least theoretically allows more than one interpretation) occurs in the claim, or where the claim as a whole includes one or more inconsistencies, to resolve that unambiguity or inconsistency”.

The subject-matter of claim 1 of the Main Request was therefore deemed not to comply with Article 123(2) EPC and the appeal was dismissed.

T 1473/19 (Schleifring GmbH) of 30.9.2022

This case concerned an opponent’s appeal against the decision of the Opposition Division to reject the opposition to a contested European patent (EP2621341) relating to a contactless rotary joint for use, for example, in a CT scanner.

Claim 1 as granted recited:

"Contactless rotary joint for a CT scanner having a stationary and a rotating part, at least the rotating part comprising: a rotary joint body (200) of a plastic material, said body having a free inner bore holding a capacitive data link having a data transmission line (110) for transmission of data, and holding a rotating transformer having a rotating transformer magnetic core (220), for transmission of electrical power, having at least one winding (221, 222); the contactless rotary joint being characterized by at least one shield (141, 142) being provided for shielding electrical and/or magnetic fields generated by the rotating transformer, to reduce interference with the capacitive data link, and by at least one shield having a higher thermal conductivity than the rotary joint body (200) and adapted to help dissipating heat from the rotating transformer, said shield being thermally connected to the rotating transformer core."

The feature of claim 1 as granted in question is:

“…said body having a free inner bore holding a capacitive data link having a data transmission line (110) for transmission of data”.

The appellant (opponent) and respondent (patent proprietor) both submitted two different interpretations of this feature. In particular, the appellant asserted that the feature should be interpreted as (a) “the body has a free inner bore and this bore holds a capacitive data link”, whereas the respondent asserted that the feature should be interpreted as (b) “the body has a free inner bore and, additionally, the body holds a capacitive data link”. The latter interpretation was previously accepted by the Opposition Division, however the Board of Appeal disagreed.

The Reasons for the Decision indicated that, in the absence of a comma between noun groups "said body", "a free inner bore" and "a capacitive data link", the skilled person “would simply consider the subject governing each present participle to be the noun group immediately preceding it, following the usual rule that modifiers are generally placed next to the word they modify” and would consequently interpret the claim as (a) “the body has a free inner bore and that this bore holds a capacitive data link”. This feature was not disclosed in the application as filed.

The Board noted that while the description and the drawings should indeed be taken into account when interpreting claim 1, doing so would not lead to the rejection of interpretation (a). In particular the Board stated: “[t]he description and the drawings do not contain anything which makes interpretation (a) appear technically nonsensical or incompatible with the claimed invention. The description does not contain a definition of the contested feature either. The mere mention, by way of example, of an embodiment which comprises a capacitive data link not arranged in accordance with interpretation (a) is not a sufficient reason to apply interpretation (b) instead of interpretation (a).”

The subject-matter of claim 1, as granted, was therefore deemed not to comply with Article 123(2) EPC, the decision under appeal was therefore set aside and the contested patent revoked.

These Decisions illustrate the EPO’s strict approach to added matter. They also highlight that it will not necessarily be possible to use the teaching of any accompanying description in a defence against an added matter attack. In summary, this developing line of case law from the Boards of Appeal emphasises the importance of accuracy when drafting and amending claims, especially when it comes to punctuation.

Why not just add the necessary comma(s)?

It could be assumed that if the above claims were amended to include the necessary comma(s), then the amended claims would comply with Article 123(2) EPC and so be allowable, for example by amending:

• claim 1 of EP1798872 to recite “(g) evaluating a preference to determine a preferred network of the plurality of transmission networks, wherein the preference comprises a preference list identifying a selection of the plurality of broadcast networks in order of preference, and identifying the highest in preference of the plurality of broadcast networks in the preference list that is available”; or
• claim 1 of EP2621341 to recite "said body having a free inner bore, said body holding a capacitive data link".

However, under Article 123(3) EPC, a European patent may not be amended in such a way as to extend the protection it confers. Both of the above proposed amendments remove a limiting feature (deemed unallowable under Article 123(2) EPC); but in doing so, broaden the claim scope of the respective patents and thus contravene Article 123(3) EPC – this is the so-called Article 123(2)-123(3) EPC “inescapable trap”.

The attorneys at Secerna LLP have a wealth of experience in considering and navigating possible added matter objections at the EPO. If you would like any further information, please do not hesitate to contact us at docketing@secerna.co.uk.