In T 411/89 the board had to decide whether the amendment of a product-by-process claim from "obtained" to "obtainable" extended the protection conferred by the patent. The board took the view that the protection was not extended because the amendment did not modify the definition of the product which was claimed per se from the beginning and because the process used for its characterisation remained the same.

In a large number of decisions (see in this chapter II.A.6.3.1) the boards interpreted the claims in the light of the description and drawings in order to establish whether they were clear and concise.