In
T 150/82 (OJ 1984, 309) the board ruled that claims relying on references to the description in the specification in respect of all their technical features (so called "omnibus claims") were unallowable as contrary to
R. 29(4) and
R. 29(6) EPC 1973 (
R. 43 EPC, unchanged), unless absolutely necessary, e.g. when a plurality of conditions would not lend themselves to verbal expression without such a reference. Examples of such exceptions included inventions containing features or limitations which could only be expressed by means of drawings or graphs defining a particular shape or a plurality of conditions. In
T 271/88 the board upheld
T 150/82 and decided that it was not possible to base claims on an appendix showing structural chemical formulae designated as "chemical formulae incorporated within claims". The board held that it was quite evident that the terms "description" and "drawing" in
R. 29(6) EPC 1973 were meant to cover structural chemical formulae (see also
T 752/94).