For the usefulness of PCT Chapter II for the applicant, see the Euro-PCT Guide, points 297-301 300-304.
In its capacity as an International Preliminary Examining Authority (i.e. under Chapter II of the PCT), the EPO is empowered to carry out international preliminary examination (IPE), the objective of which is to formulate a preliminary and non-binding opinion on whether the claimed invention appears to be novel, to involve an inventive step and to be industrially applicable. When appropriate an opinion will also be given on added subject-matter, unity, insufficient disclosure and clarity or support issues, as well as formal defects.
The international preliminary examination does not lead to either a grant or a refusal of a patent; instead, at the end of the procedure, a report – the IPRP Chapter II or IPER – is established. The procedure under Chapter II allows the applicant to submit amendments and arguments in response to the WO-ISA and, if applicable, to a WO-IPEA, which will be taken into account when establishing the report.