Selecting From Lists At The EPO – The "Two-Lists Principle"

The European Patent Office (EPO) has a reputation for applying a strict approach to assessment of basis for amendment under added matter (Article 123(2) EPC). EPO law dictates that there must be "direct and unambiguous basis" for amendments in the application as filed and the bar for meeting that standard is high.  Much of the EPO case law around this provision has focussed on what constitutes direct and unambiguous basis, and from within this developing legal framework has emerged some useful rules of thumb that can provide guidance for both European and overseas patent practitioners alike.

Selecting subject matter from lists has direct relevance to the examination of added matter and novelty. This is because creating a new combination by selecting features from one or more lists will either mean: a) the amendment will add matter where the lists in question are in the patent application as filed; or b) the amendment will impart novelty where the lists in question are