3.4 Assessment of impermissible extension of the protection conferred 

In view of the above considerations, all amendments made to claims and any connected amendments to the description and drawings in the course of opposition proceedings, such as a change in the technical features of the invention, must be examined to determine whether such amendments could result in the extension of the subject-matter beyond the content of the application as originally filed (Art. 123(2)) or in the extension of the protection conferred (Art. 123(3)).

If, in view of Art. 84, the application documents have been adapted to amended claims before grant, thereby deleting part of the subject-matter originally disclosed in order to avoid inconsistencies in the patent specification, as a rule, subject-matter deleted for this reason cannot be reinserted either into the patent specification or into the claims as granted without infringing Art. 123(3) (the cut-off effect). An analogous finding applies to subject-matter retained in the patent specification during such adaptation for reasons of comprehensibility, but indicated as not relating to the claimed invention (see T 1149/97).

The requirements of Art. 123(2) and Art. 123(3) have to be dealt with separately:

(a)Examination for compliance with Art. 123(2) is conducted in the same way as in examination proceedings.

(b)Examination for compliance with Art. 123(3), on the other hand, is based on the claims as granted, or as amended in opposition or earlier limitation proceedings, where necessary using the description and drawings to interpret the claims (Art. 69 and the Protocol on the Interpretation of Art. 69).

A composition which is specified in a claim as comprising a component in an amount which is defined by a numerical range of values is subject to an implicit proviso excluding the presence of that component in an amount outside of that range. An amendment restricting the breadth of that component, for instance by narrowing down a generic class or a list of chemical compounds defining that component, has the consequence of limiting the scope of this implicit proviso. However, a composition which is defined as comprising the components indicated in the claim is open to the presence of any further components unless otherwise specified. Therefore in a claim directed to such an openly defined composition, the restriction of the breadth of a component present therein may have the effect of broadening the scope of protection of that claim, with the consequence that in opposition/appeal proceedings such amended claim may extend the protection conferred by the granted patent (Art. 123(3)) (see T 2017/07 and T 287/11). Restricting the breadth of the component means that certain materials are no longer explicitly limited by the claim and therefore can be present in amounts which were excluded from the granted claim.