T 0536/88 (Dust-tight folding carton) of 14.01.1991

I. Documents cited in the contested European patent are in principle not automatically scrutinised in opposition or opposition appeal proceedings.

II. A document indicated in the European patent as the closest or important prior art for the purposes of elucidating the technical problem set out in the description nevertheless forms part of the opposition or opposition appeal proceedings even if not expressly cited within the opposition period (follows Decision T 198/88 dated 3 August 1989, OJ EPO 1991, 254).