This article first appeared in Intellectual Property Focus Europe 2017 published by Managing Intellectual Property

Marco Lissandrini of Bugnion investigates the complicated question of permissible modifications to European patents and patent applications

Legal framework
The main provision establishing the right to amend a patent application or a patent is Article 123 EPC, which includes three paragraphs:

• The European patent application or European patent may be amended in proceedings before the European Patent Office, in accordance with the Implementing Regulations. In any event, the applicant shall be given at least one opportunity to amend the application of his own volition.
• The European patent application or European patent may not be amended in such a way that it contains subject-matter which extends beyond the content of the application as filed.
• The European patent may not be amended in such a way as to extend the protection it confers.

Paragraph (1) includes a restriction in time, that is when amendments may be carried out, and it allows amendments to the European patent application or the European patent in all proceedings before the European Patent Office (EPO); this means that amendments may be permitted
during examination, opposition and appeal proceedings. Paragraph 1 further specifies that the applicant must be given at least one opportunity
to amend the application of his/her own volition. This means that, even when no objections are raised in the search opinion (whereby no invitation to correct any deficiencies is put forward), the applicant has the right to file voluntary amendments, without the need to ask for the consent to the examining division.

Paragraph 2 limits the impact of the amendments on the European patent application or the European patent, in the sense that the amendments
cannot introduce subject-matter not disclosed in the application as filed.

Paragraph 3 applies to granted European patents and limits the impact of the amendments by prohibiting any extension of the scope of protection conferred by the patent as granted.

The legal framework for amendments further includes several auxiliary provisions, such as those contained in Article 14 paragraph 2 (correction of errors of translation), Rule 137 (time frame for carrying out amendments), Rule 138 (different amendments for different states), Rule 139 (correction of errors in documents filed with the EPO) and Rule 140 (correction of errors in decisions of the EPO).

Corrections versus amendments
When modifications are to be carried out on a European patent application or European patent, the distinction between ‘amendments’ and ‘corrections’ is very important. This is because it affects the choice of the provisions under which the request for modification should be asked,
either Article 123 (with relating Rules 137 and 138 and specific deadlines for amendments) or Rule 139 (and in that case Article 14(2), anyway with no deadlines for making the corrections).

Unfortunately, the EPC neither defines the terms ‘amendment’ and ‘correction’, nor establishes a relationship between them.

Fortunately, through the EPO case law (Decision J8/80), it is possible to figure out meaningful definitions for ‘amendment’ and ‘correction’.

On one hand, an ‘amendment’ to a document should be interpreted as a change of mind of the applicant/proprietor or as a subsequent
development of plans for improving the applicant’s/proprietor’s position.

On the other hand, a ‘correction’ of a document should be interpreted as a restoration into conformity with the true intention of the applicant/proprietor, for example for putting right an incorrect statement or adding omitted matter. Hence, dealing with an ‘unexpressed volition’ (‘an intention’), in principle a correction might include something not disclosed in the filed documents (such as an omitted priority claim). For this reason, the proposed correction must be examined very carefully, in order to ascertain whether it hides a change of mind of the
applicant/proprietor or it represents an actual restoration of the document into conformity with his true intention. Furthermore, a correction is assessed differently, depending on the fact that it affects the application/patent (claims, description, drawings) or collateral documents
(such as the request for grant).

Where errors or mistakes concern documents other than the claims, description or drawings (for example, a missing priority claim), the proposed correction may be derived from a global assessment of the circumstances involved and it should be presented to the EPO in such a way that the latter is able to check and be convinced that: (i) a mistake was made; (ii) what the mistake was; and (iii) what the correction should be.

Instead, if the claims, description or drawings are concerned, the error must be obvious, in the sense that the skilled person must be in no doubt that the information is not correct and, at the same time, in no doubt on what the correction is (‘is’ and not ‘should be’). In this regard, a good rule of thumb is the following: if the error becomes apparent only in the light of the proposed correction, then the correction is not self-evident and must be ruled out (G3/89). Therefore, at the end of the day, the correction of errors in the claims, description or drawings must have a declaratory nature.

Attention should be paid to the fact that an apparently obvious mistake might not be so obvious indeed.

For example, assume that the description contains the following expression: 1+1=3. Probably, the most of us would immediately propose
the following correction: 1+1=2.

Are we sure that such a correction is self-evident, which means that it has a declaratory nature?

Not so sure. What about these: 1+2=3 or 2+1=3 or 1+1<3…?

If more than one possibility of correction can be foreseen, then the error is not that obvious. In this situation, the proposed correction might still be admitted, but as long as it is proposed as an amendment complying with article 123 (and not as a simple correction!), meaning that the applicant/proprietor has to prove that the amendment is derivable from the application as filed.

The disclosure test or gold standard for assessing the extension of subject-matter
The EPO is known for being very strict in assessing the provision of Article 123(2) EPC.

The principle for such a strict interpretation can be found in the task of the EPO to guarantee legal certainty to third parties, who can rely only upon the application as filed, being the ‘file estoppel’ not available under the EPC.
Furthermore, the EPO aims to prohibit unwarranted advantages for the applicant, who is supposed to be rewarded with an exclusive right for what was invented at the time of filing and not afterwards. In this regard, the EPO wants to prevent the applicant being rewarded for an invention made ex-post, for example after a critical review of the state of the art that usually emerges during examination or post-grant proceedings.

In view of these principles, the case-law of the EPO Boards of Appeal (G11/91; G3/98; G1/03; G2/10) has established the use of the so-called disclosure-test or gold standard.

Hence, for the time being, the disclosure-test is the generally accepted test for any amendment.

Getting down to brass tacks, the formulation of the disclosure-test is the following: an amendment should be regarded as introducing subject-matter that extends beyond the content of the application as filed, if the overall change in the content of the application results in the skilled person being presented with information that is not directly and unambiguously derivable – seen objectively and relative to the date of filing – from the whole content of the application as filed, even when account is taken of any feature that is implicit to a person skilled in the art using common general knowledge.

A good way to appreciate the disclosure-test is to cut it down into single concepts, with the help of the WH-questions.
Let’s get the analysis started:

An amendment should be regarded as introducing subject-matter that extends beyond the content of the application as filed, if:

What: the overall change in the content of the application, that is the outcome of an amendment in terms of the technical information
presented;

Who: the skilled person being presented with information, which means that the outcome of an amendment must be assessed from the point of view of the skilled person;

How: information which is not directly and unambiguously derivable, which means that the outcome of an amendment must be a priori straightforward and explicit in view of the disclosed invention; in other words, if additional technically relevant information become apparent to the skilled person after the amendment is carried out, then the amendment must be ruled out;

Where: from the whole content of the application as filed, which means that the outcome of an amendment must be found in the application as filed and it cannot be derived from the priority document, the abstract, the title or the documents cross referenced in the description (in the latter case, unless no doubt exists for the skilled person that such documents are part of the application);

When: seen objectively and relative to the date of filing, that is the content of the application must be read bearing in mind the technical knowledge and the state of the art available at the date of filing, and not afterwards. In other words, if a new technology has been invented after the date of filing, none of its technical implications can be kept in the background for interpreting the content of an application/patent. In this regard, the so-called common general knowledge can be used to interpret the teaching of the technical information presented in the application/patent and to put them in the context, but it cannot be used to bridge any gap in the technical information.

In view of the concepts embedded in the disclosure-test, it emerges that the assessment of amendments must be carried out focusing on the actual teaching conveyed by the original disclosure, the structure of the claims not being detrimental to what is really disclosed (T2619/11).

As an immediate consequence, the literal support is not required (T667/08, T583/09, T2296/08), contrary to the misconception widely spread outside Europe.

Finally, it is to be noted that, besides the amendments, the disclosure-test also applies to the assessment of:

• the content of prior art documents in order to evaluate their impact on the patentability of a claimed invention;
• the validity of a priority claim, namely to ascertain whether the features of an invention can be found in the priority application; and
• the validity of a divisional application (Article 76(1) EPC), namely to ascertain whether the content of the divisional application can be found in the parent application.

Amendments and extent of the patent protection
As already cited, paragraph 3 of Article 123 states: ‘The European patent may not be amended in such a way as to extend the protection it confers.’

This provision applies to claims, description and drawings, both in opposition and limitation proceedings before the EPO.

The principle at the basis of this provision is to give ultimate legal certainty to third parties, so that to exclude that an activity or a product not infringing the patent before the amendments does actually infringe the patent after the amendments have been carried out.

Combining the provisions of paragraphs 2 and 3 of Article 123, the following awkward situation occurs.

Let’s assume that a limiting feature that extends the subject-matter is introduced in a claim during the examination and that the patent then is granted. Now, let’s also suppose that the feature should be removed in subsequent opposition proceedings, because it is duly contested by the opponent. But pursuant to paragraph 3 of Article 123, the removal of the feature – which should actually be removed! – is not permitted.

This is the so-called inescapable trap of Article 123(2)(3): with or without the removal, the patent is revoked.

In fact, if the feature were not removed, the patent would contain subject-matter that extends beyond the content of the application as filed. On the
other hand, if the feature were removed, the scope of patent protection would be extended.

The trap is caused both by the examiner, who granted the patent, and by the applicant who introduced fresh subject-matter.

Hence, in opposition proceedings, bear in mind that an attack on the ground that the patent contains fresh subject-matter can be strengthened by the use of the provision under Article 123 paragraph 3.

A similar situation occurs when, during examination, a first feature in a claim is replaced with a second feature that extends the subject-matter and nevertheless the patent is granted. In opposition, the restoration of the first feature, in place of the second one, is not permitted, because the amended claim would cover a different and alternative embodiment with respect to the embodiment claimed in the patent as granted, thus extending the scope of protection of the patent.

Therefore, whenever possible, it is strongly suggested to carry out amendments by grouping together different claims, rather than to develop new esoteric wording for defining an embodiment.

In view of this, both the deletion of a feature and an intermediate generalisation are far less risky: should the subject matter extend beyond the application as filed, the solution is merely to restore the deleted feature or to add the features previously left out (intermediate restriction, see above), thus limiting – and not extending – the protection conferred by the patent.

Tips to take away
It is of the utmost importance when drafting the European patent application to pave the way towards reliable amendments, should there be
the need to circumvent prior art cited during examination or post-grant proceedings.

First of all, our suggestion is to disclose all the main features of the invention, even though they are not actually claimed. Whenever possible, each feature should be introduced standalone, preferably in the ‘summary of invention’, for avoiding any objection of ‘intermediate generalisation’. Possible wording is ‘according to one aspect…’, ‘according to a further aspect…’, ‘As a general concept, the invention comprises the following aspect…’ and similar. In my opinion, the word ‘aspect’ is better than ’embodiment’ – at least in the summary – because ’embodiment’ might take for granted the presence of a mutual relation among other features previously introduced. When the figures are described, which surely illustrate ’embodiments’, a good wording might be ‘the drawings illustrate embodiments of the disclosure and, together with the description, serve to explain the principles of the disclosure’.

Secondly, a ‘good’ set of dependent claims, in term of scope of protection, clarity and dependency, should be drafted: grouping together the claims is easy and prevents any objection under Article 123 paragraphs 2 and 3.

Finally, avoid any statement that, even implicitly, might depict a feature as an essential feature for an embodiment; should that be the case, you may want to delete the feature from an embodiment, but, if that feature is perceived as essential, the deletion would be impossible (see essentiality-test).