3. Clarity of claims
3.2. Relative qualities and vaguely formulated claims
In the key decision T 728/98 (OJ 2001, 319) the board held that it followed from the requirement of legal certainty that a claim could not be considered clear within the meaning of Art. 84 EPC 1973 if it comprised an unclear technical feature (here "substantially pure") for which no unequivocal generally accepted meaning existed in the relevant art. This applied all the more if the unclear feature was essential for delimiting the subject-matter claimed from the prior art (see also T 1399/11, T 1702/15). According to the board in T 869/20, T 728/98 did not conclude that clarity should only be examined when the unclear feature is the sole differentiating feature, but simply stressed that in such case the requirement of clarity is particular important to ensure legal certainty.
Likewise in T 226/98 (OJ 2002, 498) the board held that the feature "as a pharmaceutical product" for defining a pharmaceutical standard of purity in a claim related to a product as such (here, famotidine form "B"), rendered said claim unclear in the absence of a generally accepted quantitative definition for the purported standard of purity. Also in T 174/02 ("[in] quick [succession]"), T 1640/11 ("value"), T 842/14 ("accurate"), T 1963/17 ("substantially simultaneously"), T 362/17 ("brief [history of spoken words]"), T 1903/19 ("low intensity"), T 1152/21 ("appropriate temperature", "about 70°C", "about 3 hours") the boards ruled that the relative terms at issue were unclear.
In T 1469/20 the board held that the terms "inexpensive", "swift", "wide variety" and "pleasant association" in claim 1 were not clear. The fact that the claim could be interpreted, essentially by disregarding the relative and subjective terms which were not clearly limiting, did not mean that the claim could be allowed as it stood. The board pointed out that clarity is a requirement separate from novelty and inventive step, and allowing unclear terms to remain in the claim places an undue burden on the reader seeking to determine the scope of protection. The fact that "inexpensive" and "pleasant association" were non-technical concepts which as such did not count for inventive step, did not matter for the question of clarity.
In T 586/97 the main claim was directed to an aerosol composition comprising a propellant and an active ingredient which was not defined. The board held that, when an essential ingredient comprised in a chemical composition is open to be labelled arbitrarily "active ingredient" or not, the meaning of that feature would be variable. Leaving the public in doubt as to which compositions are covered by the claim would be at variance with the principle of legal certainty. Therefore, the claim at issue failed to meet the requirement of clarity imposed by Art. 84 EPC 1973. See also T 642/05, T 134/10.
In decisions T 1129/97 (OJ 2001, 273) and T 274/98 the board emphasised that, to satisfy the clarity requirement, the group of compounds/ingredients according to the claim had to be defined in such a way that the skilled person could clearly distinguish compounds/ingredients that belonged to the claimed group from those that did not (see also T 425/98 regarding the expression "consisting of a major amount of").
In T 268/13 the board concluded that a claim to a "method for producing a [...] decorative strip having a [...] structure consisting of a text or graphic symbol [...]" satisfied the requirements of Art. 84 EPC 1973. Although it was impossible to give an entirely general, universally applicable definition of what constituted a symbol, in the case in hand it would be clear whether or not a particular character was a symbol in the given cultural, linguistic or technical context. The claim therefore presented neither somebody wanting to avoid infringing the patent nor a court deciding on infringement with an impossible task.
In T 1845/11 the board concluded that the term "Asian race" was not clear. Clearly defined objective criteria for patient assignment into racial groups were not available to the skilled person.
In T 860/93 (OJ 1995, 47) the board decided as follows: where a quality is expressed in a claim as being within a given numerical range, the method for measuring that quality must be general technical knowledge, so that no explicit description is needed, or a method of measuring that quality needs to be identified (decision T 124/85 followed). In contrast, where a claim specifies a relative quality, in this case that the products should be "water-soluble", it is not normally necessary to identify any method for its determination (for the term "soluble" see also T 785/92, T 939/98, T 125/15). In the following cases the boards confirmed that the use of a relative term in a claim may be accepted where the skilled person is able to understand the meaning of this term in a given context: T 860/95 ("for a long period of time"), T 649/97 ("transparent"), T 1041/98 ("thin plate"), T 193/01 ("thin film"), T 545/01 ("flat"), T 378/02 ("smooth"), T 2367/16 ("overnight") and T 2402/17 (relationship between the terms "higher" and "lower oscillation susceptibility" and "smaller values"). In T 1045/92 the claims concerned "a two-pack type curable composition comprising [...]". In the board's view "a two-pack curable composition" was an item of commerce as familiar to readers skilled in the polymer art as everyday articles were to the public at large. The claim was therefore clear.
In T 1170/16 it was held that "useful for" in the expression "a liquid absorbent structure useful for absorbent articles" of claim 1 resulted in a lack of clarity. "Useful for" included an element of value with respect to the features it linked. In claim 1 this benefit was not defined and so the reader was left in the dark as to how the structure was useful for the absorbent articles. The board did not accept that "useful for" was synonymous with "for", meaning "suitable for". It had an effect going beyond mere suitability. In T 1526/22 the examining division had objected to the wording [apparatus] "for a motor vehicle driver assistance for an ego vehicle" in the claim because this suggested that an effect supporting motor vehicle assistance was to be produced, which was however not apparent from the wording of the claim. The board interpreted the wording of claim 1 as meaning an apparatus suitable for a motor vehicle driver assistance system for an ego vehicle, as is usual for a purpose feature in an apparatus claim in the form "apparatus for ...". Claim 1 did not require the claimed apparatus to be configured to provide the output of the state estimator as input to a driver assistance system. The board did not see a lack of clarity in that respect.
In T 651/05 the board found that the introduction of vague terms created a lack of clarity due to different but equally valid interpretations (see also T 621/03, T 127/04). In T 1534/10 a claim contained the feature "that the data carrier (1) is constructed in a multi-layered manner as a laminate and contains at least two films (4, 5) which are integrated as a cover film (4) or as a core film (5) into the layer construction of the laminated data carrier". The board considered this wording ambiguous because it combined a plural form ("at least two films (4, 5)") with a singular form ("as a cover film (4) or as a core film (5)"), making it unclear whether the "at least two films" were each either a cover film or a core film, or whether together they formed a new film that was then either a cover film or a core film.
Where, on one of several possible constructions of a vaguely formulated claim, part of the subject-matter claimed is not sufficiently described to be carried out, the claim is open to objection under Art. 100(b) EPC 1973 (T 1404/05, see also chapter II.C.8.1. "Article 83 EPC and support from the description").
In T 1065/18 the board held that due to its wording ("Pharmaceutical composition ... packed or filled into a container"), the claim put the emphasis on a pharmaceutical composition rather than a container comprising said composition. This made it unclear whether the protection sought was limited to the pharmaceutical composition per se, or whether a container comprising a pharmaceutical composition was to be protected (see T 352/04 for a similar case). Thus, the claim lacked clarity.
- T 2387/22
In T 2387/22 claim 1 according to auxiliary requests 9 to 11 defined the use of a Vacuum Metallised Pigment (VMP) in a flexographic ink formulation for providing the following technical effects: "fewer print defects, higher hiding and stronger colour and allowing a lower volume anilox". The respondent (patent proprietor) submitted that according to G 2/88, when a use claim defined technical purposes or effects, these were to be interpreted as functional features restricting the scope of protection.
According to the appellant (opponent) these functional features did not meet the requirement of clarity under Art. 84 EPC, since they were defined using relative terms as well as diffusely defined concepts. The respondent replied that it was a well-established practice of the boards to allow the definition of effects or purposes in non-medical use claims using broad and/or relative terms.
The board observed that there was no basis – be it in the case law or in the EPC – for concluding that the limiting functional features of a use claim are exempt from the clarity requirement under Art. 84 EPC or somehow exposed to lower standards in this respect. It however emphasised that – irrespective of whether a claim was directed to a use or to any other category of subject-matter – the mere breadth of protection did not in itself imply a lack of clarity. The decisive consideration was whether the feature(s) in question gave(s) rise, or could plausibly give rise, to legal uncertainty when assessing whether a particular subject-matter falls within or outside the scope of protection conferred by the claim.
Moreover, the board stated that, where the invention was based on the discovery of a new technical effect of a known entity (as in G 2/88 and G 6/88), it was generally accepted in practice to define that effect in correspondingly broad terms, provided the effect was sufficiently distinct to clearly delimit the scope of protection with respect to the prior art. The situation in the present case was, however, fundamentally different. The use claim did not seek to define distinct technical effects, but rather relative improvements in the achievement of such effects..
The board held that where a claimed invention is defined by the use of a known entity to achieve a known technical effect or purpose, and the alleged technical contribution lies in a relative improvement or enhancement of that effect or purpose, the requirement of clarity under Art. 84 EPC generally demands that the feature defining such relative improvement or enhancement be expressed in objectively verifiable terms, thereby ensuring legal certainty regarding the scope of protection. In these "relative-improvement" scenarios, any imprecise functional language could blur the distinction between claimed and known uses, giving rise to the very legal uncertainty that the clarity requirement is intended to prevent.
In the present case, the board concluded that no objective criteria were available for determining when the number of print defects, the degree of hiding, the colour intensity or the anilox volume could be regarded as sufficiently low or high for other uses to fall within or outside the scope of the claim. As a result, the subject-matter of claim 1 could not be assessed objectively in relation to the prior art, which gave rise to legal uncertainty and therefore failed to meet the clarity requirement of Art. 84 EPC.