T 0337/95 (Lower alkyl) du 30.01.1996

1. Claims have to be clear for the sake of legal certainty (Nos. 2.2 to 2.4 of the reasons).

2.Since, in the absence of any unambiguous reference point, a relative term such as "lower alkyl" in the field of organic chemistry does not have a generally accepted meaning with respect to its maximum number of carbon atoms, such a term is ambiguous and therefore not suitable for clearly defining the subject-matter for which protection is sought in a claim which is directed to a group of organic compounds per se (No. 2.8 of the reasons).