In T 762/90
a lack of clarity was found in the use of a trade mark designating a whole series of products which differed from one another depending on phases in their industrial development. Moreover, the board expressed doubts about the use of such a designation, since it was uncertain whether the meaning of the trade mark would remain unaltered up to the end of the patent term (see also T 939/92
). Similarly, in T 480/98
the board considered that a trade mark product referred to in the characterising portion of claim 1 did not have a clear technical meaning, in that it could refer to a plurality of products having different compositions and properties. In consequence there was a lack of clarity, and the claim was not allowable. According to the board in T 623/91
the exclusion of a composition by reference to the trade mark or trade designation would not introduce uncertainty and therefore not offend against Art. 84 EPC 1973
, as changes in the range of chemical composition would not be likely without a corresponding change in the trade name or trade mark.