4.2 Presenting your invention
4.2.6Claims
4.2.019Wherever appropriate, claims should consist of two parts (see the examples in Annex II), a prior art portion and a characterising portion. In the first claim and all other independent claims, the prior art portion should designate the subject-matter of the invention and the technical features which are needed to define it but which, in combination, form part of the prior art. The characterising portion should state the technical features for which protection is sought in combination with the features in the prior art portion.
4.2.021A European patent application may not contain more than one independent claim in the same category (e.g. product and/or process) unless one of the exceptions applies. See point 5.2.011 for further information.
Dependent claims should include all the features of the claim to which they relate. They must contain, if possible at the beginning, a reference to this other claim, which may also be dependent, and then state the additional features for which protection is sought.
As far as possible, all dependent claims referring back to one or more previous claims must be grouped together in the most appropriate way.
4.2.023As Article 84 requires claims to be concise (a requirement that applies both to the claims in their entirety and to each claim individually), you must keep the number of claims reasonable in consideration of the nature of the invention you wish to protect. You should therefore avoid undue repetition resulting from the use of independent claims in the same category or a proliferation of dependent claims.
The scope defined by the claims must be as precise as the invention allows. As a general rule, claims which attempt to define the invention in terms of the result to be achieved are not allowed. Where the invention relates to a chemical product, it may be defined by its chemical formula or as a product of a process or, exceptionally, in terms of its parameters.
GL F‑IV, 4.10-4.16
Furthermore, references to the description or drawings, particularly in the form of "as described in part ... of the description" or "as illustrated in figure ... of the drawings", are not allowed unless they are absolutely indispensable.
4.2.026However, in a European patent application containing drawings, reference signs linking the claims to the drawings should be placed in brackets after the technical features mentioned in the claims if this makes the claims easier to understand. Reference signs are not to be construed as limiting the claims.
4.2.027In exceptional circumstances, a European patent application or patent may include separate sets of claims for specific designated states (see point 4.2.039).