The requirement that the claims must be clear applies to individual claims, i.e. to independent and dependent claims alike, and also to the claims as a whole. The clarity of the claims is of the utmost importance in view of their function in defining the matter for which protection is sought. Therefore, the meaning of the terms of a claim must, as far as possible, be clear for the person skilled in the art from the wording of the claim alone (see also F‑IV, 4.2). In view of the differences in the scope of protection which may be attached to the various categories of claims, the division must ensure that the wording of a claim leaves no doubt as to its category.[Art. 84; ]
Where it is found that the claims lack clarity under Art. 84, this may have led to the issuing of a partial European or supplementary European search report under Rule 63 (see B‑VIII, 3.1 and B-VIII, 3.2). In such cases, in the absence of appropriate amendment and/or convincing arguments from the applicant as to why the invitation under Rule 63(1) was not justified, an objection under Rule 63(3) will also arise (see H‑II, 5).
Source: http://www.epo.org/law-practice/legal-texts/html/guidelines/e/f_iv_4_1.htm
Date retrieved: 17 May 2021