In the case of Chroman Derivatives/Merck, a chemical Appeal Board was confronted with deciding what remedies were available in a case where a chemical formula was wrongly presented in a European application as filed, the correct formula only being determined sometime after the application was filed.

The Appeal Board held that replacement of the incorrect formula with the correct formula would be an impermissible change even if evidence showed that by following the teaching of the specification one would have inevitably produced the compounds in question. The Board rejected the argument that such disclosure made the correct formula an inherent teaching of the application because such a correction would present "technically relevant information which the skilled person could not derive from the original documents" and thus had the effect of adding subject matter to the application.

The Board did, however, hold that if the specification gave sufficient directions that by following them the same compounds would inevitably be obtained, then claims in the form "chroman derivatives obtainable by the following process steps ..." would be acceptable.