2.1.1 Voluntary and mandatory comments and amendments

In accordance with their right under the PCT (Art. 28(1) PCT in combination with Rule 52 PCT and Art. 41(1) PCT in combination with Rule 78.1(b) PCT), and irrespective of whether Rule 161(1) or (2) applies, applicants are entitled to file any comments and amendments to the application documents (the claims, the description and the drawings) they wish for the purposes of the European grant proceedings. Under these PCT provisions, as implemented by Rule 161, applicants are entitled to submit (further) comments on any finding and to file (further) amendments as they see fit within the six-month period under Rules 161 and 162, regardless of whether the EPO acted as (S)ISA or IPEA in the international phase, and regardless of whether the EPO or another International Authority arrived at any negative finding in the WO‑ISA, SISR or IPER. If under Rule 161 any comments or amendments are filed in accordance with Art. 28(1) PCT or Art. 41(1) PCT, i.e. without any obligation to do so, they are referred to as "voluntary" comments and amendments (OJ EPO 2010, 316 and 406; OJ EPO 2009, 533).

Rule 161(1) applies to applications for which the EPO acted as (S)ISA and, if a demand for this was filed, as IPEA (A‑XIV, 3). If the EPO acting as (S)ISA or IPEA issued a negative opinion, applicants are obliged to file (also) a reply, i.e. comments and/or amendments, to the deficiencies noted by the EPO in the WO‑ISA, SISR or IPER within the time limit under Rules 161 and 162. In other words, the comments and amendments filed in response to a negative opinion are mandatory.

Rule 161(2) applies to applications for which the EPO did not act as (S)ISA (A‑XIV, 4). In these cases, any comments and amendments filed under Rule 161(2), whether or not in response to any results of the international phase processing, are always voluntary.