For general information on third-party observations in the PCT phase, see GL/PCT‑EPO E-II.
PCT AI Part 8
If the formalities officer forwards third-party observations to the examiner before a final report (ISR, SISR or IPER) is established, the examiner should consider them in the same way as he would in the European procedure (see GL/EPO E‑VI, 3). However, given that under the PCT third-party observations should refer to novelty or inventive step only, their relevance will in most cases depend on the relevance of the prior-art documents in support of them. Any document(s) provided to the examiner with the observations will either have been received from the IB or obtained by the formalities officer.
Third-party observations will normally not reach the examiner at the international search stage if the ISR is established and received by the IB on time, namely before publication of the application. However, this may happen when the international search is performed after an A2 publication.
If the third-party observations are relevant, the documents will be cited in the ISR and in section V of the WO‑ISA. The examiner will take the third-party observations and the applicant's comments, if present, into account when drafting the WO‑ISA.
If the third-party observations are not relevant or not sufficiently understandable, the documents will not be included in the ISR. The examiner will insert a comment in section V of the WO‑ISA indicating that the third-party observations have been taken into account and found not to be relevant or that the third-party observations could not be taken into account, together with the reasons.