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The European Patent Office (EPO) provided updated guidelines to its Examiners with several changes over the current Guidelines. The changes in Part F, Chapter IV, 4.3 (iii) are particularly worthy of note and are explained above. These changes equate to a formalizing of practices, relating to description amendments, that have become increasingly common in recent years.
This article views the possible consequences and risks of these “new” practices and ends with practical points to keep in mind in view of this new risks.
In European prosecution, when the final scope of the claims is agreed, applicants are often requested to bring the description into conformity with the claims. This is to satisfy the requirement of Article 84 EPC: that the claims be supported by the description. Previously, this requirement was considered satisfied by relatively minor amendments. For example, for a large specification, a statement might be added to direct a reader’s attention to the most relevant parts of the description, so readers could quickly comprehend the operation of the invention.
Outside opposition proceedings and rare clashes relating to whether parts of a description were incompatible with claims, this old practice was relatively straightforward.
Proposals or requests to make severe description amendments have however become increasingly frequent in recent years. It is also increasingly common to see proposed, or requested, amendments that while unobjectionable from a prosecution viewpoint have the potential to cause problems for applicants after grant. An example of such an amendment is the insertion of the phrase “the preamble of claim 1 is disclosed in [D1]”, which might be alleged in opposition to be an acknowledgement of the closest prior-art, and even has the potential to add matter if the teaching of [D1] adjusts the construction of claimed terms.
Generally, EPO practice is characterized by a claim-centric approach. Indeed, European prosecution often requires definitions from the description to be added to the claims so the claims can be understood without any reference to the description. It is therefore surprising to see the new Guidelines commit so strongly to this increased focus on the description.
Outside the remit of the EPO, in infringement proceedings of EPC states, the description is very important. In accordance with Article 69(1) EPC, the description and figures shall be used to interpret the claims and thereby derive the extent of protection. Some EPC states also have doctrines of equivalents and the extent of these may be at least partly defined by the description.
For example, since the UK Supreme Court’s Actavis decision in 2017, the UK has a doctrine of equivalents. The limits of this doctrine are still being defined by UK case law. However, the Actavis decision itself made clear that the prosecution history (including description amendments) will be considered if the “patentee had made it clear to the EPO that he was not seeking to contend that his patent, if granted, would extend its scope to the sort of variant which he now claims infringes”. An example of such consideration is found in the 2020 Akebia vs Fibrogen decision, in which Lord Justice Arnold used an amendment in prosecution as one of several reasons to limit the scope of equivalents. This decision also noted the following principle from German case law:
“If the description discloses a plurality of possibilities for achieving a specific technical effect, but only one of those possibilities is catered for in the patent claim, the utilisation of any of the other possibilities properly does not constitute infringement of the patent with equivalent means.”
Whilst a similar principle is not binding in the UK (yet) it is an indication of how some in the UK judiciary are thinking about equivalents. This indication has been further supported by the recent judgment in Facebook Ireland vs Voxer IP
Given the above, it is clear the deletion or explicit disclaiming of an embodiment from the description is likely to risk a reduction in the scope of protection afforded by a patent.
The new Guidelines also seem to encourage Examiners to object to subtle description amendments.
To address such objections might require comments to be put on the public register about the potential construction of the patent according to national law. This is something few patentees are likely to want to do – such comments could jeopardize the future assertion of patent families worldwide.
It is unclear how strictly the new Guidelines will be implemented and how required description amendments will be considered by some national courts. Therefore, it is difficult to make recommendations. The following points are however worth keeping in mind:
The Good News
If the new Guidelines are enforced without flexibility, it is likely that a lot of appeals will follow and possibly even adverse commentary in national law decisions.
Happily, despite the EPO not considering infringement, most European Examiners are commercially savvy and fully appreciative of the legal pressures on applicants and attorneys. A pragmatic approach to description amendment is hoped for and would seem reasonable, at least until the ramifications of such amendments are fully apparent. It would also seem reasonable to take account of the fact that many applications that are currently being prosecuted were filed before the advice of the new Guidelines was available to applicants.
For their part, attorneys should advise clients of the new practices and associated risks. This will help applicants prepare accordingly and hopefully avoid serious problems in the future.

Murgitroyd is a leading intellectual property firm supporting innovative businesses across a wide range of sectors. From patents and trade marks to designs, copyright, and IP strategy, their expertise extends beyond legal protection to helping organisations maximise the value of their ideas. Working across industries such as life sciences, engineering, technology, and creative sectors, Murgitroyd combines technical insight with commercial understanding to deliver tailored, forward-thinking solutions.