At the examination stage of a European patent application an additional search may be necessary. The reasons for such an additional search may be, for example:
(i)amendment of claims so that they embrace matter not covered by the original search (see, however, C‑III, 3.1.1 C‑III, 3.2.1 and H‑II, 7.1 H‑II, 6.1 for claims not searched because of lack of unity and H‑II, 6.2 H‑IV, 4.1.2 for amendments introducing subject-matter from the description resulting in claims defining subject-matter which is not linked by a single general inventive concept to the subject-matter originally searched);
(ii)removal by amendment or rebuttal, during substantive examination, of the deficiencies which resulted in the issuance of an incomplete search or a declaration taking the place of a search report under Rule 63, or a declaration under Art. 17(2)(a) PCT or Art. 17(2)(b) PCT (see B‑VIII and C‑IV, 7.2 C‑IV, 7.3);
(iii)reversal, by the examining division, of an opinion of the search division with respect to novelty or lack of inventive step (see B‑III, 1.1) or on other issues (see B‑III, 1.2), in particular lack of unity of invention (see B‑VII), exclusions from the search (see B‑III, 3.11 and B‑VIII) or Rule 62a; and
(iv)limitations or imperfections in the initial search.
The examining division makes use of documents found in such an additional search, where they are considered relevant to the examination of the application. Where a new document is used in the examination procedure, a copy must be communicated to the applicant (Art. 113(1)).
In a similar way, an additional search may become necessary during examination of oppositions against a European patent (see D‑VI, 5).