The search division also makes positive statements on patentability in the search opinion, where applicable. The level of detail is such as to assist applicants in their decision-making. Therefore, it is not necessary to provide such detailed reasoning as for a negative objection, but a mere statement without any explanation is sufficient only if the reason is immediately apparent.
Source: http://www.epo.org/law-practice/legal-texts/html/guidelines/e/b_xi_3_2_2.htm
Date retrieved: 17 May 2021