Drafting a patent specification fit for prosecution and enforcement internationally

Guidelines for drafting patent specifications are often based upon lessons learnt the hard way. Drafting “rules” for specific territories are formulated based upon experience of patent applications undergoing rigorous examination at the patent office and of patents coming under intense scrutiny in contentious proceedings, including oppositions and in court proceedings.

Such guidelines represent a valuable insight into what works and does not work in a patent specification. However, treating a set of guidelines as a set of “dos and don’ts” to be blindly followed can cause issues. This is especially the case if the same patent specification is to be filed in multiple territories.

There have long been differences between the approaches of the patent offices and courts of the “big 5” patent territories (USA, Europe, Japan, Korea and China). One such difference is the approach to added subject matter. Another is the importance of data supporting the claimed subject matter. It is sometimes felt that the requirements of the different patent offices are incompatible and that it is becoming increasingly challenging to draft a patent specification that is suitable for all territories. 

For example, the style of drafting originating from the US, as a result of guidelines produced in response to decisions handed down by the Federal Circuit in patent cases, is creating increasing problems when the equivalent cases are prosecuted before the European Patent Office. A patent specification that has been drafted to provide a reservoir of features that are to be selected at will and combined can run into significant difficulties before the EPO whose strict approach to added subject matter means that the Examiners are looking for disclosure of combinations of features to support amendments.

However, the problems really only arise where a specification is drafted with just one territory’s requirements in mind. In practice, the different requirements of patent offices can often be accommodated in a single specification, but this requires careful consideration and a good understanding of both the invention to be protected and the different requirements of the patent offices. The different drafting styles and requirements need to be combined and refined without losing sight of the subtleties of the invention that is to be protected. 

Consider the following requirements:

Requirement 1

In the United States, in order to avoid a narrow interpretation of the invention, it is important to include discussion of the various features of the invention whilst avoiding the suggestion that features of the invention are essential. This includes avoiding statements about “the invention” and using language that emphasizes the optional nature of features. 

Requirement 2

Particularly with European practice in mind, in order to provide flexibility to file amendments during prosecution, it is imperative that different levels of detail and specificity are provided. Intermediate generalisations are of particular value, as is the description of combinations of features and specific embodiments. It is helpful to explain how the invention works and what effects the invention seeks to achieve, although this must be balanced with the detrimental effects in other territories of making “promises”.

This is not incompatible with Requirement 1. Both styles of disclosure may be accommodated in a single specification. However, to ensure that the discussion of specific embodiments and combinations of features is not damaging to Requirement 1, it is important to make it clear that this more specific disclosure is not intended to be limiting.

Requirement 3

The inclusion of supporting data and specific examples are of great importance in the prosecution, particularly in Japan and China. Data is often essential to demonstrate that the invention involves an inventive step. Here, it is important not only to disclose the combinations of features that provide a desired effect, but also to demonstrate that the desired effect has been achieved. If possible, it should also be explained how one can reasonably extrapolate from the examples in the specification, to support the grant of claims that cover more than just the examples.

Requirement 4

It is helpful during the prosecution in many territories to be able to point to the technical effect of the invention and to an advantage that the claimed invention offers over the prior art. This information will often make it easier to convince the examiner that the claimed subject matter involves an inventive step. However, it is important that this discussion of the technical effect and advantages over the prior art is not included in the Background section of the specification. It is generally also desirable to make sure that it is not suggested that all embodiments must enjoy the discussed benefits or provide the discussed technical effects.

Our attorneys have many years’ experience of combining these requirements to provide patent specifications that can be successfully prosecuted in key patent territories around the world. They are acutely aware of the importance of preparing a specification that will form a solid foundation upon which to build patent rights. As a result of this experience, our attorneys not only draft new patent specifications, but are also frequently asked to review and revise specifications that have been drafted by others (usually prior to filing a PCT application) in order to ensure that they are in the best possible shape for successful prosecution and enforcement in Europe and beyond.

If you have any questions, please do not hesitate to contact one of our patent attorneys. We will be delighted to help you to draft patent specifications or to adapt existing specifications.