3.3 Exceptions where a reply to the Rule 161(1) invitation is not required
3.3.2 Positive WO‑ISA, SISR or IPER
Where the WO‑ISA, any supplementary international search report (SISR) or, where applicable, the subsequent IPER prepared by the EPO was positive (according to the same principles explained for European search opinions in B‑XI, 3.9), the applicant is still sent a communication according to Rule 161(1), but is not required to respond to it.
No communication under Rules 161(1) and Rule 162 is issued if applicants have explicitly waived their right to these and have already paid any claims fees due (see E‑IX, 3.2).
3.3.3Rule 161 communication issued before 1 April 2010
In cases where the Rule 161 communication was already issued before 1 April 2010, there is no requirement to respond to the WO-ISA prepared by the EPO or to the IPER prepared by the EPO as IPEA; if the applicant has not filed any amendments or comments upon entry into the regional phase before the EPO, the first communication will essentially be based on the content of said WO-ISA or IPER prepared by the EPO.