If the Search Division considers that the European application does not comply with the requirement of unity of invention (see C-III, 7), it must search it, and draw up the partial European search report under Rule 46(1), for those parts of the application which relate to the invention (or group of inventions forming unity) first mentioned in the claims. The partial European search report is supplemented with a specification of the separate inventions.

With regard to the search opinion in cases of a lack of unity of invention, see XII, 6.

When determining which invention is the invention or unitary group of inventions first mentioned in the claims, the examiner takes account of the content of the dependent claims, disregarding trivial claims (see III, 3.8).