The question of the extent to which the technical information and examples adduced in the description may be generalised in the formulation of the claims is usually examined in the context of the requirements of Art. 83 EPC (see in particular chapter II.C.5. "Clarity and completeness of disclosure"). Sometimes though it is also considered in the context of the requirement for support by the description. See also chapter II.C.8. "The relationship between Article 83 and Article 84 EPC".

In T 2231/09 the patent concerned a method of representing and analysing images. Claim 1 of the main request set out that "... at least one said descriptor element is derived using only a subset of pixels in said image." The appellant had put forward an interpretation according to which a "subset" could correspond to all pixels in the image, which the board considered inconsistent with essential parts of the described embodiments. The board stressed that, while a certain degree of generalisation may be permitted, features as claimed should make it possible to clearly identify features of embodiments that are covered by the terms of a claim. Moreover, the generalised subject-matter as claimed should make it possible to understand the technical problem to be solved. The terms of a claim should be commensurate with the invention's technical contribution to the art. The board regarded the division of the image into regions and subsets as essential for achieving the technical effect underlying the invention. Therefore, claim 1 was not supported by the description and did not comply with Art. 84 EPC 1973.

In T 659/93 the board held that the requirement that the claims should be supported by the description meant that they had not only to contain all the features presented as essential in the description, but had also to reflect the applicants' effective contribution by enabling the skilled person to carry out their teaching throughout the field to which they applied (similarly T 332/94 with reference to T 409/91, OJ 1994, 653).

In T 939/92 (OJ 1996, 309) the examining division had raised the objection that the disputed claim was an unreasonable generalisation of the examples contained in the description. However, the board held that it did not follow from Art. 84 EPC 1973 that a claim was objectionable just because it was "unreasonably broad". The expression "supported by the description" meant that the technical features stated in the description as being essential features of the invention described must be the same as those used to define the invention in the claims, for otherwise the claims would not be true definitions but mere descriptions. If a claim concerned a group of chemical compounds per se, an objection of lack of support by the description could not properly be raised for the sole reason that the description did not contain sufficient information in order to make it credible that an alleged technical effect (which was not, however, a part of the definition of the claimed compounds) was obtained by all the compounds claimed (see, with regard to Art. 83 EPC, also T 2001/12). The facts of the case in question differed from those underlying T 409/91.

In T 94/05 the board pointed out that the requirement for the claims to be supported by the description was intended to ensure that the extent of protection as defined by the patent claims corresponds to the technical contribution of the disclosed invention to the art (see also T 409/91, T 435/91). Therefore the claims must reflect the actual contribution to the art in such a way that the skilled person is able to perform the invention in the entire range claimed (T 659/93). In the board's view, a purely formal support by the description, i.e. a verbatim repetition of the mention of a claimed feature, could not meet these requirements. To be allowable, functional features must disclose a clear teaching which the skilled person can carry out without undue burden (see T 68/85, OJ 1987, 228). From this, it followed that the skilled person, at least after reading the patent specification, taking account of his common general knowledge, and possibly also after carrying out normal experiments, must actually be provided with at least a plurality of different embodiment variants. The reproducibility from the patent specification of the above-mentioned functionally defined feature was confined to the sole embodiment described. The board concluded that the functional definition in claim 1 did not adequately reflect the technical contribution described in the patent specification. Moreover, claim 1 and the description were contradictory, so that the claim was not supported by the description and the requirements under Art. 84 EPC were not met.

In T 568/97 the claims defined the physiological effect to be achieved by a sufficiently high concentration of vasoactive intestinal polypeptide and/or prostaglandins as active agents in a pharmaceutical composition for transurethral administration. Neither individual values nor ranges of the amounts of vasoactive intestinal polypeptide and/or prostaglandins were disclosed in the patent. Furthermore, it was impossible to find out without undue burden the physiologically effective amounts as claimed merely on the basis of common general knowledge. The board held that the description of the patent lacked support within the meaning of Art. 84 EPC 1973 as to the amount of vasoactive intestinal polypeptide and/or prostaglandins required to achieve a physiologically effective dose. The functional feature not only had to be such that the skilled person could understand it; he also had to be able to implement it.

In T 484/92 the board concluded that, in contrast to T 409/91, the requirement of support by the description had been met and the appellant was entitled to claim the alleged invention in broad functional terms, i.e. in terms of the desired end effect, because, having disclosed one mechanism for achieving that goal, there were alternative ways of performing the invention at the disposal of the person skilled in the art, which would become apparent to him upon reading the description, based on his common general knowledge.