2.1 Subject-matter of the search; restrictions 

Once the search division has determined the subject-matter of the invention as outlined in B‑IV, 1.1, its first step is to define its approach to the search ‒ in terms of what concepts, classes, keywords, etc. it plans to use ‒ as precisely as possible. Often, one or more of the claims themselves can be used for this, but they may have to be generalised in order to cover all aspects and embodiments of the invention. At this point, the search division should also think about whether there is any non-patentable subject-matter (see B‑VIII, 1 and B-VIII, 2) or any lack of unity of invention (see B‑VII, 1.1). It may also have to restrict the search because claims have to be regarded as abandoned (see B‑III, 3.4), because the application falls so short of the EPC requirements that a meaningful search is impossible (see B‑VIII, 3) or because the application does not comply with Rule 43(2) (see the procedure described in B‑VIII, 4). If the search is restricted, this must be mentioned in the search report or the declaration replacing it under Rule 63. The declaration must indicate the reasons for any restrictions under Rule 63 (see B‑X, 8(iii)). The declaration or the partial search report is then treated as the search report for the purposes of the subsequent proceedings.